diff --git a/conf/wide.go b/conf/wide.go
index 7f6c679..8ec9492 100644
--- a/conf/wide.go
+++ b/conf/wide.go
@@ -29,8 +29,8 @@ import (
 	"time"
 
 	"github.com/b3log/wide/event"
+	"github.com/b3log/wide/log"
 	"github.com/b3log/wide/util"
-	"github.com/golang/glog"
 )
 
 const (
@@ -93,6 +93,7 @@ type conf struct {
 	Context               string  // server context
 	Server                string  // server host and port ({IP}:{Port})
 	StaticServer          string  // static resources server scheme, host and port (http://{IP}:{Port})
+	LogLevel              string  // logging level
 	Channel               string  // channel (ws://{IP}:{Port})
 	HTTPSessionMaxAge     int     // HTTP session max age (in seciond)
 	StaticResourceVersion string  // version of static resources
@@ -111,6 +112,9 @@ var Wide conf
 // Save function will use this variable to persist.
 var rawWide conf
 
+// Logger.
+var logger = log.NewLogger(os.Stdout)
+
 // FixedTimeCheckEnv checks Wide runtime enviorment periodically (7 minutes).
 //
 // Exits process if found fatal issues (such as not found $GOPATH),
@@ -129,14 +133,14 @@ func checkEnv() {
 	cmd := exec.Command("go", "version")
 	buf, err := cmd.CombinedOutput()
 	if nil != err {
-		glog.Fatal("Not found 'go' command, please make sure Go has been installed correctly")
+		logger.Error("Not found 'go' command, please make sure Go has been installed correctly")
 
 		os.Exit(-1)
 	}
-	glog.V(5).Info(string(buf))
+	logger.Debug(string(buf))
 
 	if "" == os.Getenv("GOPATH") {
-		glog.Fatal("Not found $GOPATH, please configure it before running Wide")
+		logger.Error("Not found $GOPATH, please configure it before running Wide")
 
 		os.Exit(-1)
 	}
@@ -147,7 +151,7 @@ func checkEnv() {
 	if nil != err {
 		event.EventQueue <- &event.Event{Code: event.EvtCodeGocodeNotFound}
 
-		glog.Warningf("Not found gocode [%s]", gocode)
+		logger.Warnf("Not found gocode [%s]", gocode)
 	}
 
 	ideStub := util.Go.GetExecutableInGOBIN("ide_stub")
@@ -156,7 +160,7 @@ func checkEnv() {
 	if nil != err {
 		event.EventQueue <- &event.Event{Code: event.EvtCodeIDEStubNotFound}
 
-		glog.Warningf("Not found ide_stub [%s]", ideStub)
+		logger.Warnf("Not found ide_stub [%s]", ideStub)
 	}
 }
 
@@ -192,7 +196,7 @@ func (c *conf) GetGoFmt(username string) string {
 			case "goimports":
 				return util.Go.GetExecutableInGOBIN("goimports")
 			default:
-				glog.Errorf("Unsupported Go Format tool [%s]", user.GoFormat)
+				logger.Errorf("Unsupported Go Format tool [%s]", user.GoFormat)
 				return "gofmt"
 			}
 		}
@@ -234,13 +238,13 @@ func Save() bool {
 	bytes, err := json.MarshalIndent(rawWide, "", "    ")
 
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 
 		return false
 	}
 
 	if err = ioutil.WriteFile("conf/wide.json", bytes, 0644); nil != err {
-		glog.Error(err)
+		logger.Error(err)
 
 		return false
 	}
@@ -254,29 +258,31 @@ func Load(confPath, confIP, confPort, confServer, confStaticServer, confContext,
 
 	err := json.Unmarshal(bytes, &Wide)
 	if err != nil {
-		glog.Error("Parses wide.json error: ", err)
+		logger.Error("Parses wide.json error: ", err)
 
 		os.Exit(-1)
 	}
 
+	log.SetLevel(Wide.LogLevel)
+
 	// keep the raw content
 	json.Unmarshal(bytes, &rawWide)
 
-	glog.V(5).Info("Conf: \n" + string(bytes))
+	logger.Debug("Conf: \n" + string(bytes))
 
 	// Working Driectory
 	Wide.WD = util.OS.Pwd()
-	glog.V(5).Infof("${pwd} [%s]", Wide.WD)
+	logger.Debugf("${pwd} [%s]", Wide.WD)
 
 	// IP
 	ip, err := util.Net.LocalIP()
 	if err != nil {
-		glog.Error(err)
+		logger.Error(err)
 
 		os.Exit(-1)
 	}
 
-	glog.V(5).Infof("${ip} [%s]", ip)
+	logger.Debugf("${ip} [%s]", ip)
 
 	if confDocker {
 		// TODO: may be we need to do something here
@@ -374,7 +380,7 @@ func UpdateCustomizedConf(username string) {
 
 	t, err := template.ParseFiles("static/user/style.css.tmpl")
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 
 		os.Exit(-1)
 	}
@@ -382,14 +388,14 @@ func UpdateCustomizedConf(username string) {
 	wd := util.OS.Pwd()
 	dir := filepath.Clean(wd + "/static/user/" + u.Name)
 	if err := os.MkdirAll(dir, 0755); nil != err {
-		glog.Error(err)
+		logger.Error(err)
 
 		os.Exit(-1)
 	}
 
 	fout, err := os.Create(dir + PathSeparator + "style.css")
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 
 		os.Exit(-1)
 	}
@@ -397,7 +403,7 @@ func UpdateCustomizedConf(username string) {
 	defer fout.Close()
 
 	if err := t.Execute(fout, model); nil != err {
-		glog.Error(err)
+		logger.Error(err)
 
 		os.Exit(-1)
 	}
@@ -435,12 +441,10 @@ func CreateWorkspaceDir(path string) {
 func createDir(path string) {
 	if !util.File.IsExist(path) {
 		if err := os.MkdirAll(path, 0775); nil != err {
-			glog.Error(err)
+			logger.Error(err)
 
 			os.Exit(-1)
 		}
-
-		glog.V(7).Infof("Created a directory [%s]", path)
 	}
 }
 
diff --git a/conf/wide.json b/conf/wide.json
index 436274c..696eac3 100644
--- a/conf/wide.json
+++ b/conf/wide.json
@@ -4,6 +4,7 @@
     "Context": "",
     "Server": "{IP}:{Port}",
     "StaticServer": "",
+    "LogLevel": "info",
     "Channel": "ws://{IP}:{Port}",
     "HTTPSessionMaxAge": 86400,
     "StaticResourceVersion": "${time}",
diff --git a/editor/editors.go b/editor/editors.go
index 044b6ca..b485f0a 100644
--- a/editor/editors.go
+++ b/editor/editors.go
@@ -29,12 +29,15 @@ import (
 
 	"github.com/b3log/wide/conf"
 	"github.com/b3log/wide/file"
+	"github.com/b3log/wide/log"
 	"github.com/b3log/wide/session"
 	"github.com/b3log/wide/util"
-	"github.com/golang/glog"
 	"github.com/gorilla/websocket"
 )
 
+// Logger.
+var logger = log.NewLogger(os.Stdout)
+
 // WSHandler handles request of creating editor channel.
 // XXX: NOT used at present
 func WSHandler(w http.ResponseWriter, r *http.Request) {
@@ -58,7 +61,7 @@ func WSHandler(w http.ResponseWriter, r *http.Request) {
 
 	session.EditorWS[sid] = &editorChan
 
-	glog.Infof("Open a new [Editor] with session [%s], %d", sid, len(session.EditorWS))
+	logger.Infof("Open a new [Editor] with session [%s], %d", sid, len(session.EditorWS))
 
 	args := map[string]interface{}{}
 	for {
@@ -72,7 +75,7 @@ func WSHandler(w http.ResponseWriter, r *http.Request) {
 
 		offset := getCursorOffset(code, line, ch)
 
-		// glog.Infof("offset: %d", offset)
+		// logger.Infof("offset: %d", offset)
 
 		gocode := util.Go.GetExecutableInGOBIN("gocode")
 		argv := []string{"-f=json", "autocomplete", strconv.Itoa(offset)}
@@ -91,7 +94,7 @@ func WSHandler(w http.ResponseWriter, r *http.Request) {
 		ret = map[string]interface{}{"output": string(output.Bytes()), "cmd": "autocomplete"}
 
 		if err := session.EditorWS[sid].WriteJSON(&ret); err != nil {
-			glog.Error("Editor WS ERROR: " + err.Error())
+			logger.Error("Editor WS ERROR: " + err.Error())
 			return
 		}
 	}
@@ -102,7 +105,7 @@ func AutocompleteHandler(w http.ResponseWriter, r *http.Request) {
 	var args map[string]interface{}
 
 	if err := json.NewDecoder(r.Body).Decode(&args); err != nil {
-		glog.Error(err)
+		logger.Error(err)
 		http.Error(w, err.Error(), 500)
 
 		return
@@ -121,7 +124,7 @@ func AutocompleteHandler(w http.ResponseWriter, r *http.Request) {
 	fout, err := os.Create(path)
 
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		http.Error(w, err.Error(), 500)
 
 		return
@@ -131,7 +134,7 @@ func AutocompleteHandler(w http.ResponseWriter, r *http.Request) {
 	fout.WriteString(code)
 
 	if err := fout.Close(); nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		http.Error(w, err.Error(), 500)
 
 		return
@@ -142,7 +145,7 @@ func AutocompleteHandler(w http.ResponseWriter, r *http.Request) {
 
 	offset := getCursorOffset(code, line, ch)
 
-	// glog.Infof("offset: %d", offset)
+	// logger.Infof("offset: %d", offset)
 
 	userWorkspace := conf.Wide.GetUserWorkspace(username)
 	workspaces := filepath.SplitList(userWorkspace)
@@ -153,7 +156,7 @@ func AutocompleteHandler(w http.ResponseWriter, r *http.Request) {
 		libPath += userLib + conf.PathListSeparator
 	}
 
-	glog.V(5).Infof("gocode set lib-path %s", libPath)
+	logger.Debugf("gocode set lib-path [%s]", libPath)
 
 	// FIXME: using gocode set lib-path has some issues while accrossing workspaces
 	gocode := util.Go.GetExecutableInGOBIN("gocode")
@@ -169,7 +172,7 @@ func AutocompleteHandler(w http.ResponseWriter, r *http.Request) {
 
 	output, err := cmd.CombinedOutput()
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		http.Error(w, err.Error(), 500)
 
 		return
@@ -189,7 +192,7 @@ func GetExprInfoHandler(w http.ResponseWriter, r *http.Request) {
 
 	var args map[string]interface{}
 	if err := json.NewDecoder(r.Body).Decode(&args); err != nil {
-		glog.Error(err)
+		logger.Error(err)
 		http.Error(w, err.Error(), 500)
 
 		return
@@ -202,7 +205,7 @@ func GetExprInfoHandler(w http.ResponseWriter, r *http.Request) {
 	fout, err := os.Create(path)
 
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -212,7 +215,7 @@ func GetExprInfoHandler(w http.ResponseWriter, r *http.Request) {
 	fout.WriteString(code)
 
 	if err := fout.Close(); nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -223,7 +226,7 @@ func GetExprInfoHandler(w http.ResponseWriter, r *http.Request) {
 
 	offset := getCursorOffset(code, line, ch)
 
-	// glog.Infof("offset [%d]", offset)
+	// logger.Infof("offset [%d]", offset)
 
 	ideStub := util.Go.GetExecutableInGOBIN("ide_stub")
 	argv := []string{"type", "-cursor", filename + ":" + strconv.Itoa(offset), "-info", "."}
@@ -234,7 +237,7 @@ func GetExprInfoHandler(w http.ResponseWriter, r *http.Request) {
 
 	output, err := cmd.CombinedOutput()
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		http.Error(w, err.Error(), 500)
 
 		return
@@ -265,7 +268,7 @@ func FindDeclarationHandler(w http.ResponseWriter, r *http.Request) {
 
 	var args map[string]interface{}
 	if err := json.NewDecoder(r.Body).Decode(&args); err != nil {
-		glog.Error(err)
+		logger.Error(err)
 		http.Error(w, err.Error(), 500)
 
 		return
@@ -278,7 +281,7 @@ func FindDeclarationHandler(w http.ResponseWriter, r *http.Request) {
 	fout, err := os.Create(path)
 
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -288,7 +291,7 @@ func FindDeclarationHandler(w http.ResponseWriter, r *http.Request) {
 	fout.WriteString(code)
 
 	if err := fout.Close(); nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -299,7 +302,7 @@ func FindDeclarationHandler(w http.ResponseWriter, r *http.Request) {
 
 	offset := getCursorOffset(code, line, ch)
 
-	// glog.Infof("offset [%d]", offset)
+	// logger.Infof("offset [%d]", offset)
 
 	ideStub := util.Go.GetExecutableInGOBIN("ide_stub")
 	argv := []string{"type", "-cursor", filename + ":" + strconv.Itoa(offset), "-def", "."}
@@ -310,7 +313,7 @@ func FindDeclarationHandler(w http.ResponseWriter, r *http.Request) {
 
 	output, err := cmd.CombinedOutput()
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		http.Error(w, err.Error(), 500)
 
 		return
@@ -350,7 +353,7 @@ func FindUsagesHandler(w http.ResponseWriter, r *http.Request) {
 	var args map[string]interface{}
 
 	if err := json.NewDecoder(r.Body).Decode(&args); err != nil {
-		glog.Error(err)
+		logger.Error(err)
 		http.Error(w, err.Error(), 500)
 
 		return
@@ -363,7 +366,7 @@ func FindUsagesHandler(w http.ResponseWriter, r *http.Request) {
 	fout, err := os.Create(filePath)
 
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -373,7 +376,7 @@ func FindUsagesHandler(w http.ResponseWriter, r *http.Request) {
 	fout.WriteString(code)
 
 	if err := fout.Close(); nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -383,7 +386,7 @@ func FindUsagesHandler(w http.ResponseWriter, r *http.Request) {
 	ch := int(args["cursorCh"].(float64))
 
 	offset := getCursorOffset(code, line, ch)
-	// glog.Infof("offset [%d]", offset)
+	// logger.Infof("offset [%d]", offset)
 
 	ideStub := util.Go.GetExecutableInGOBIN("ide_stub")
 	argv := []string{"type", "-cursor", filename + ":" + strconv.Itoa(offset), "-use", "."}
@@ -394,7 +397,7 @@ func FindUsagesHandler(w http.ResponseWriter, r *http.Request) {
 
 	output, err := cmd.CombinedOutput()
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		http.Error(w, err.Error(), 500)
 
 		return
diff --git a/editor/formatter.go b/editor/formatter.go
index 945375b..dd89421 100644
--- a/editor/formatter.go
+++ b/editor/formatter.go
@@ -23,7 +23,6 @@ import (
 	"github.com/b3log/wide/conf"
 	"github.com/b3log/wide/session"
 	"github.com/b3log/wide/util"
-	"github.com/golang/glog"
 )
 
 // GoFmtHandler handles request of formatting Go source code.
@@ -46,7 +45,7 @@ func GoFmtHandler(w http.ResponseWriter, r *http.Request) {
 	var args map[string]interface{}
 
 	if err := json.NewDecoder(r.Body).Decode(&args); err != nil {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -62,7 +61,7 @@ func GoFmtHandler(w http.ResponseWriter, r *http.Request) {
 	fout, err := os.Create(filePath)
 
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -72,7 +71,7 @@ func GoFmtHandler(w http.ResponseWriter, r *http.Request) {
 
 	fout.WriteString(code)
 	if err := fout.Close(); nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -99,7 +98,7 @@ func GoFmtHandler(w http.ResponseWriter, r *http.Request) {
 	fout, err = os.Create(filePath)
 	fout.WriteString(code)
 	if err := fout.Close(); nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
diff --git a/event/events.go b/event/events.go
index 74a0878..2bcab64 100644
--- a/event/events.go
+++ b/event/events.go
@@ -15,7 +15,11 @@
 // Package event includes event related manipulations.
 package event
 
-import "github.com/golang/glog"
+import (
+	"os"
+
+	"github.com/b3log/wide/log"
+)
 
 const (
 	// EvtCodeGOPATHNotFound indicates an event: not found $GOPATH env variable
@@ -33,6 +37,9 @@ const (
 // Max length of queue.
 const maxQueueLength = 10
 
+// Logger.
+var logger = log.NewLogger(os.Stdout)
+
 // Event represents an event.
 type Event struct {
 	Code int         `json:"code"` // event code
@@ -63,7 +70,7 @@ var UserEventQueues = queues{}
 func Load() {
 	go func() {
 		for event := range EventQueue {
-			glog.V(5).Infof("Received a global event [code=%d]", event.Code)
+			logger.Debugf("Received a global event [code=%d]", event.Code)
 
 			// dispatch the event to each user event queue
 			for _, userQueue := range UserEventQueues {
@@ -86,7 +93,7 @@ func (uq *UserEventQueue) AddHandler(handlers ...Handler) {
 func (ueqs queues) New(sid string) *UserEventQueue {
 	q := ueqs[sid]
 	if nil != q {
-		glog.Warningf("Already exist a user queue in session [%s]", sid)
+		logger.Warnf("Already exist a user queue in session [%s]", sid)
 
 		return q
 	}
@@ -100,7 +107,7 @@ func (ueqs queues) New(sid string) *UserEventQueue {
 
 	go func() { // start listening
 		for evt := range q.Queue {
-			glog.V(5).Infof("Session [%s] received an event [%d]", sid, evt.Code)
+			logger.Debugf("Session [%s] received an event [%d]", sid, evt.Code)
 
 			// process event by each handlers
 			for _, handler := range q.Handlers {
diff --git a/file/exporter.go b/file/exporter.go
index d69703a..78c0343 100644
--- a/file/exporter.go
+++ b/file/exporter.go
@@ -21,7 +21,6 @@ import (
 	"path/filepath"
 
 	"github.com/b3log/wide/util"
-	"github.com/golang/glog"
 )
 
 // GetZip handles request of retrieving zip file.
@@ -57,7 +56,7 @@ func CreateZip(w http.ResponseWriter, r *http.Request) {
 
 	var args map[string]interface{}
 	if err := json.NewDecoder(r.Body).Decode(&args); err != nil {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -75,7 +74,7 @@ func CreateZip(w http.ResponseWriter, r *http.Request) {
 
 	zipFile, err := util.Zip.Create(path + ".zip")
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
diff --git a/file/files.go b/file/files.go
index 17b1416..e4498f9 100644
--- a/file/files.go
+++ b/file/files.go
@@ -26,11 +26,14 @@ import (
 
 	"github.com/b3log/wide/conf"
 	"github.com/b3log/wide/event"
+	"github.com/b3log/wide/log"
 	"github.com/b3log/wide/session"
 	"github.com/b3log/wide/util"
-	"github.com/golang/glog"
 )
 
+// Logger.
+var logger = log.NewLogger(os.Stdout)
+
 // Node represents a file node in file tree.
 type Node struct {
 	Name      string  `json:"name"`
@@ -120,7 +123,7 @@ func RefreshDirectory(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "application/json")
 	data, err := json.Marshal(node.Children)
 	if err != nil {
-		glog.Error(err)
+		logger.Error(err)
 		return
 	}
 
@@ -135,7 +138,7 @@ func GetFile(w http.ResponseWriter, r *http.Request) {
 	var args map[string]interface{}
 
 	if err := json.NewDecoder(r.Body).Decode(&args); err != nil {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -162,7 +165,7 @@ func GetFile(w http.ResponseWriter, r *http.Request) {
 
 		user := GetUsre(path)
 		if nil == user {
-			glog.Warningf("The path [%s] has no owner")
+			logger.Warnf("The path [%s] has no owner")
 			data["path"] = ""
 
 			return
@@ -193,7 +196,7 @@ func SaveFile(w http.ResponseWriter, r *http.Request) {
 	var args map[string]interface{}
 
 	if err := json.NewDecoder(r.Body).Decode(&args); err != nil {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -205,7 +208,7 @@ func SaveFile(w http.ResponseWriter, r *http.Request) {
 	fout, err := os.Create(filePath)
 
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -216,7 +219,7 @@ func SaveFile(w http.ResponseWriter, r *http.Request) {
 	fout.WriteString(code)
 
 	if err := fout.Close(); nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		wSession := session.WideSessions.Get(sid)
@@ -235,7 +238,7 @@ func NewFile(w http.ResponseWriter, r *http.Request) {
 	var args map[string]interface{}
 
 	if err := json.NewDecoder(r.Body).Decode(&args); err != nil {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -270,7 +273,7 @@ func RemoveFile(w http.ResponseWriter, r *http.Request) {
 	var args map[string]interface{}
 
 	if err := json.NewDecoder(r.Body).Decode(&args); err != nil {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -297,7 +300,7 @@ func RenameFile(w http.ResponseWriter, r *http.Request) {
 	var args map[string]interface{}
 
 	if err := json.NewDecoder(r.Body).Decode(&args); err != nil {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -336,7 +339,7 @@ func Find(w http.ResponseWriter, r *http.Request) {
 
 	var args map[string]interface{}
 	if err := json.NewDecoder(r.Body).Decode(&args); err != nil {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -385,7 +388,7 @@ func SearchText(w http.ResponseWriter, r *http.Request) {
 	var args map[string]interface{}
 
 	if err := json.NewDecoder(r.Body).Decode(&args); err != nil {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -429,7 +432,7 @@ func walk(path string, node *Node, creatable, removable bool) {
 		node.Children = append(node.Children, &child)
 
 		if nil == fio {
-			glog.Warningf("Path [%s] is nil", fpath)
+			logger.Warnf("Path [%s] is nil", fpath)
 
 			continue
 		}
@@ -471,7 +474,7 @@ func listFiles(dirname string) []string {
 		fio, err := os.Lstat(path)
 
 		if nil != err {
-			glog.Warningf("Can't read file info [%s]", path)
+			logger.Warnf("Can't read file info [%s]", path)
 
 			continue
 		}
@@ -562,30 +565,30 @@ func createFile(path, fileType string) bool {
 	case "f":
 		file, err := os.OpenFile(path, os.O_CREATE, 0775)
 		if nil != err {
-			glog.Error(err)
+			logger.Error(err)
 
 			return false
 		}
 
 		defer file.Close()
 
-		glog.V(5).Infof("Created file [%s]", path)
+		logger.Debugf("Created file [%s]", path)
 
 		return true
 	case "d":
 		err := os.Mkdir(path, 0775)
 
 		if nil != err {
-			glog.Error(err)
+			logger.Error(err)
 
 			return false
 		}
 
-		glog.V(5).Infof("Created directory [%s]", path)
+		logger.Debugf("Created directory [%s]", path)
 
 		return true
 	default:
-		glog.Errorf("Unsupported file type [%s]", fileType)
+		logger.Errorf("Unsupported file type [%s]", fileType)
 
 		return false
 	}
@@ -594,12 +597,12 @@ func createFile(path, fileType string) bool {
 // removeFile removes file on the specified path.
 func removeFile(path string) bool {
 	if err := os.RemoveAll(path); nil != err {
-		glog.Errorf("Removes [%s] failed: [%s]", path, err.Error())
+		logger.Errorf("Removes [%s] failed: [%s]", path, err.Error())
 
 		return false
 	}
 
-	glog.V(5).Infof("Removed [%s]", path)
+	logger.Debugf("Removed [%s]", path)
 
 	return true
 }
@@ -607,12 +610,12 @@ func removeFile(path string) bool {
 // renameFile renames (moves) a file from the specified old path to the specified new path.
 func renameFile(oldPath, newPath string) bool {
 	if err := os.Rename(oldPath, newPath); nil != err {
-		glog.Errorf("Renames [%s] failed: [%s]", oldPath, err.Error())
+		logger.Errorf("Renames [%s] failed: [%s]", oldPath, err.Error())
 
 		return false
 	}
 
-	glog.V(5).Infof("Renamed [%s] to [%s]", oldPath, newPath)
+	logger.Debugf("Renamed [%s] to [%s]", oldPath, newPath)
 
 	return true
 }
@@ -632,7 +635,7 @@ func find(dir, name string, results []*string) []*string {
 	f.Close()
 
 	if nil != err {
-		glog.Errorf("Read dir [%s] failed: [%s]", dir, err.Error())
+		logger.Errorf("Read dir [%s] failed: [%s]", dir, err.Error())
 
 		return results
 	}
@@ -655,7 +658,7 @@ func find(dir, name string, results []*string) []*string {
 			match, err := filepath.Match(strings.ToLower(pattern), strings.ToLower(path))
 
 			if nil != err {
-				glog.Errorf("Find match filename failed: [%s]", err.Error)
+				logger.Errorf("Find match filename failed: [%s]", err.Error)
 
 				continue
 			}
@@ -681,7 +684,7 @@ func search(dir, extension, text string, snippets []*Snippet) []*Snippet {
 	f.Close()
 
 	if nil != err {
-		glog.Errorf("Read dir [%s] failed: [%s]", dir, err.Error())
+		logger.Errorf("Read dir [%s] failed: [%s]", dir, err.Error())
 
 		return snippets
 	}
@@ -709,7 +712,7 @@ func searchInFile(path string, text string) []*Snippet {
 
 	bytes, err := ioutil.ReadFile(path)
 	if nil != err {
-		glog.Errorf("Read file [%s] failed: [%s]", path, err.Error())
+		logger.Errorf("Read file [%s] failed: [%s]", path, err.Error())
 
 		return ret
 	}
diff --git a/i18n/locales.go b/i18n/locales.go
index 89c7814..f5337cf 100644
--- a/i18n/locales.go
+++ b/i18n/locales.go
@@ -22,9 +22,12 @@ import (
 	"sort"
 	"strings"
 
-	"github.com/golang/glog"
+	"github.com/b3log/wide/log"
 )
 
+// Logger.
+var logger = log.NewLogger(os.Stdout)
+
 // Locale.
 type locale struct {
 	Name     string
@@ -54,7 +57,7 @@ func Load() {
 func load(localeStr string) {
 	bytes, err := ioutil.ReadFile("i18n/" + localeStr + ".json")
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 
 		os.Exit(-1)
 	}
@@ -63,14 +66,14 @@ func load(localeStr string) {
 
 	err = json.Unmarshal(bytes, &l.Langs)
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 
 		os.Exit(-1)
 	}
 
 	Locales[localeStr] = l
 
-	glog.V(5).Infof("Loaded [%s] locale configuration", localeStr)
+	logger.Debugf("Loaded [%s] locale configuration", localeStr)
 }
 
 // Get gets message with the specified locale and key.
diff --git a/log/logs.go b/log/logs.go
index 47e4dbb..ea90c40 100755
--- a/log/logs.go
+++ b/log/logs.go
@@ -14,7 +14,8 @@
 
 // Package log includes logging related manipulations.
 //
-// 	logger := log.NewLogger(os.Stdout, log.Debug)
+//  log.Level = log.Debug
+// 	logger := log.NewLogger(os.Stdout)
 //
 // 	logger.Debug("debug message")
 // 	logger.Info("info message")
@@ -28,6 +29,7 @@ import (
 	"fmt"
 	"io"
 	stdlog "log"
+	"strings"
 )
 
 // Logging level.
@@ -38,20 +40,65 @@ const (
 	Error
 )
 
-// Logger is a simple logger with level.
-// The underlying logger is the Go standard logging "log".
+// all loggers.
+var loggers []*Logger
+
+// the global default logging level, it will be used for creating logger.
+var logLevel = Debug
+
+// Logger represents a simple logger with level.
+// The underlying logger is the standard Go logging "log".
 type Logger struct {
 	level  int
 	logger *stdlog.Logger
 }
 
 // NewLogger creates a logger.
-func NewLogger(out io.Writer, level int) *Logger {
-	ret := &Logger{level: level, logger: stdlog.New(out, "", stdlog.Ldate|stdlog.Ltime|stdlog.Lshortfile)}
+func NewLogger(out io.Writer) *Logger {
+	ret := &Logger{level: logLevel, logger: stdlog.New(out, "", stdlog.Ldate|stdlog.Ltime|stdlog.Lshortfile)}
+
+	loggers = append(loggers, ret)
 
 	return ret
 }
 
+// SetLevel sets the logging level of all loggers.
+func SetLevel(level string) {
+	logLevel = getLevel(level)
+
+	for _, l := range loggers {
+		l.SetLevel(level)
+	}
+}
+
+// getLevel gets logging level int value corresponding to the specified level.
+func getLevel(level string) int {
+	level = strings.ToLower(level)
+
+	switch level {
+	case "debug":
+		return Debug
+	case "info":
+		return Info
+	case "warn":
+		return Warn
+	case "error":
+		return Error
+	default:
+		return Info
+	}
+}
+
+// SetLevel sets the logging level of a logger.
+func (l *Logger) SetLevel(level string) {
+	l.level = getLevel(level)
+}
+
+// IsDebugEnabled determines whether the debug level is enabled.
+func (l *Logger) IsDebugEnabled() bool {
+	return l.level <= Debug
+}
+
 // Debug prints debug level message.
 func (l *Logger) Debug(v ...interface{}) {
 	if Debug < l.level {
diff --git a/main.go b/main.go
index b264ff8..d4fc24f 100644
--- a/main.go
+++ b/main.go
@@ -33,14 +33,17 @@ import (
 	"github.com/b3log/wide/event"
 	"github.com/b3log/wide/file"
 	"github.com/b3log/wide/i18n"
+	"github.com/b3log/wide/log"
 	"github.com/b3log/wide/notification"
 	"github.com/b3log/wide/output"
 	"github.com/b3log/wide/session"
 	"github.com/b3log/wide/shell"
 	"github.com/b3log/wide/util"
-	"github.com/golang/glog"
 )
 
+// Logger
+var logger *log.Logger
+
 // The only one init function in Wide.
 func init() {
 	confPath := flag.String("conf", "conf/wide.json", "path of wide.json")
@@ -52,16 +55,16 @@ func init() {
 	confChannel := flag.String("channel", "", "this will overwrite Wide.XXXChannel if specified")
 	confStat := flag.Bool("stat", false, "whether report statistics periodically")
 	confDocker := flag.Bool("docker", false, "whether run in a docker container")
-
-	flag.Set("alsologtostderr", "true")
-	flag.Set("stderrthreshold", "INFO")
-	flag.Set("v", "3")
+	//     confLogLevel := flag.String("log_level", "info", "logging level: debug/info/warn/error")
 
 	flag.Parse()
 
+	log.SetLevel("warn")
+	logger = log.NewLogger(os.Stdout)
+
 	wd := util.OS.Pwd()
 	if strings.HasPrefix(wd, os.TempDir()) {
-		glog.Error("Don't run wide in OS' temp directory or with `go run`")
+		logger.Error("Don't run wide in OS' temp directory or with `go run`")
 
 		os.Exit(-1)
 	}
@@ -105,7 +108,7 @@ func indexHandler(w http.ResponseWriter, r *http.Request) {
 	username := httpSession.Values["username"].(string)
 	user := conf.Wide.GetUser(username)
 	if nil == user {
-		glog.Warningf("Not found user [%s]", username)
+		logger.Warnf("Not found user [%s]", username)
 
 		http.Redirect(w, r, conf.Wide.Context+"login", http.StatusFound)
 
@@ -121,12 +124,12 @@ func indexHandler(w http.ResponseWriter, r *http.Request) {
 		"pathSeparator": conf.PathSeparator, "codeMirrorVer": conf.CodeMirrorVer,
 		"user": user, "editorThemes": conf.GetEditorThemes()}
 
-	glog.V(3).Infof("User [%s] has [%d] sessions", username, len(wideSessions))
+	logger.Debugf("User [%s] has [%d] sessions", username, len(wideSessions))
 
 	t, err := template.ParseFiles("views/index.html")
 
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		http.Error(w, err.Error(), 500)
 
 		return
@@ -164,7 +167,7 @@ func startHandler(w http.ResponseWriter, r *http.Request) {
 	sid := r.URL.Query()["sid"][0]
 	wSession := session.WideSessions.Get(sid)
 	if nil == wSession {
-		glog.Errorf("Session [%s] not found", sid)
+		logger.Errorf("Session [%s] not found", sid)
 	}
 
 	model := map[string]interface{}{"conf": conf.Wide, "i18n": i18n.GetAll(locale), "locale": locale,
@@ -173,7 +176,7 @@ func startHandler(w http.ResponseWriter, r *http.Request) {
 	t, err := template.ParseFiles("views/start.html")
 
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		http.Error(w, err.Error(), 500)
 
 		return
@@ -205,7 +208,7 @@ func keyboardShortcutsHandler(w http.ResponseWriter, r *http.Request) {
 	t, err := template.ParseFiles("views/keyboard_shortcuts.html")
 
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		http.Error(w, err.Error(), 500)
 
 		return
@@ -238,7 +241,7 @@ func aboutHandler(w http.ResponseWriter, r *http.Request) {
 	t, err := template.ParseFiles("views/about.html")
 
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		http.Error(w, err.Error(), 500)
 
 		return
@@ -253,8 +256,6 @@ func main() {
 
 	initMime()
 
-	defer glog.Flush()
-
 	// IDE
 	http.HandleFunc(conf.Wide.Context+"/", handlerGzWrapper(indexHandler))
 	http.HandleFunc(conf.Wide.Context+"/start", handlerWrapper(startHandler))
@@ -321,11 +322,11 @@ func main() {
 	http.HandleFunc(conf.Wide.Context+"/signup", handlerWrapper(session.SignUpUser))
 	http.HandleFunc(conf.Wide.Context+"/preference", handlerWrapper(session.PreferenceHandler))
 
-	glog.Infof("Wide is running [%s]", conf.Wide.Server+conf.Wide.Context)
+	logger.Infof("Wide is running [%s]", conf.Wide.Server+conf.Wide.Context)
 
 	err := http.ListenAndServe(conf.Wide.Server, nil)
 	if err != nil {
-		glog.Fatal(err)
+		logger.Error(err)
 	}
 }
 
@@ -390,7 +391,7 @@ func stopwatch(handler func(w http.ResponseWriter, r *http.Request)) func(w http
 		start := time.Now()
 
 		defer func() {
-			glog.V(5).Infof("[%s] [%s]", r.RequestURI, time.Since(start))
+			logger.Debugf("[%s] [%s]", r.RequestURI, time.Since(start))
 		}()
 
 		handler(w, r)
diff --git a/notification/notifications.go b/notification/notifications.go
index ecb79c4..68b9772 100644
--- a/notification/notifications.go
+++ b/notification/notifications.go
@@ -17,15 +17,16 @@ package notification
 
 import (
 	"net/http"
+	"os"
 	"strconv"
 	"time"
 
 	"github.com/b3log/wide/conf"
 	"github.com/b3log/wide/event"
 	"github.com/b3log/wide/i18n"
+	"github.com/b3log/wide/log"
 	"github.com/b3log/wide/session"
 	"github.com/b3log/wide/util"
-	"github.com/golang/glog"
 	"github.com/gorilla/websocket"
 )
 
@@ -38,6 +39,9 @@ const (
 	server = "Server" // notification.type: server
 )
 
+// Logger.
+var logger = log.NewLogger(os.Stdout)
+
 // Notification represents a notification.
 type Notification struct {
 	event    *event.Event
@@ -74,7 +78,7 @@ func event2Notification(e *event.Event) {
 		notification = &Notification{event: e, Type: server, Severity: error,
 			Message: i18n.Get(locale, "notification_"+strconv.Itoa(e.Code)).(string) + " [" + e.Data.(string) + "]"}
 	default:
-		glog.Warningf("Can't handle event[code=%d]", e.Code)
+		logger.Warnf("Can't handle event[code=%d]", e.Code)
 
 		return
 	}
@@ -105,7 +109,7 @@ func WSHandler(w http.ResponseWriter, r *http.Request) {
 
 	session.NotificationWS[sid] = &wsChan
 
-	glog.V(4).Infof("Open a new [Notification] with session [%s], %d", sid, len(session.NotificationWS))
+	logger.Debugf("Open a new [Notification] with session [%s], %d", sid, len(session.NotificationWS))
 
 	// add user event handler
 	wSession.EventQueue.AddHandler(event.HandleFunc(event2Notification))
diff --git a/output/outputs.go b/output/outputs.go
index ff93f09..1def94e 100644
--- a/output/outputs.go
+++ b/output/outputs.go
@@ -32,9 +32,9 @@ import (
 
 	"github.com/b3log/wide/conf"
 	"github.com/b3log/wide/i18n"
+	"github.com/b3log/wide/log"
 	"github.com/b3log/wide/session"
 	"github.com/b3log/wide/util"
-	"github.com/golang/glog"
 	"github.com/gorilla/websocket"
 )
 
@@ -43,6 +43,9 @@ const (
 	lintSeverityWarn  = "warning" // lint severity: warning
 )
 
+// Logger.
+var logger = log.NewLogger(os.Stdout)
+
 // Lint represents a code lint.
 type Lint struct {
 	File     string `json:"file"`
@@ -66,7 +69,7 @@ func WSHandler(w http.ResponseWriter, r *http.Request) {
 
 	session.OutputWS[sid] = &wsChan
 
-	glog.V(4).Infof("Open a new [Output] with session [%s], %d", sid, len(session.OutputWS))
+	logger.Debugf("Open a new [Output] with session [%s], %d", sid, len(session.OutputWS))
 }
 
 // RunHandler handles request of executing a binary file.
@@ -77,7 +80,7 @@ func RunHandler(w http.ResponseWriter, r *http.Request) {
 	var args map[string]interface{}
 
 	if err := json.NewDecoder(r.Body).Decode(&args); err != nil {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 	}
 
@@ -95,13 +98,13 @@ func RunHandler(w http.ResponseWriter, r *http.Request) {
 
 	stdout, err := cmd.StdoutPipe()
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 	}
 
 	stderr, err := cmd.StderrPipe()
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 	}
 
@@ -109,7 +112,7 @@ func RunHandler(w http.ResponseWriter, r *http.Request) {
 	errReader := util.NewReader(stderr)
 
 	if err := cmd.Start(); nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 	}
 
@@ -124,7 +127,7 @@ func RunHandler(w http.ResponseWriter, r *http.Request) {
 
 			err := wsChannel.WriteJSON(&channelRet)
 			if nil != err {
-				glog.Error(err)
+				logger.Error(err)
 				return
 			}
 
@@ -143,7 +146,7 @@ func RunHandler(w http.ResponseWriter, r *http.Request) {
 		defer util.Recover()
 		defer cmd.Wait()
 
-		glog.V(5).Infof("Session [%s] is running [id=%d, file=%s]", sid, runningId, filePath)
+		logger.Debugf("Session [%s] is running [id=%d, file=%s]", sid, runningId, filePath)
 
 		// push once for front-end to get the 'run' state and pid
 		if nil != wsChannel {
@@ -151,7 +154,7 @@ func RunHandler(w http.ResponseWriter, r *http.Request) {
 			channelRet["output"] = ""
 			err := wsChannel.WriteJSON(&channelRet)
 			if nil != err {
-				glog.Error(err)
+				logger.Error(err)
 				return
 			}
 
@@ -170,14 +173,14 @@ func RunHandler(w http.ResponseWriter, r *http.Request) {
 					// remove the exited process from user process set
 					processes.remove(wSession, cmd.Process)
 
-					glog.V(5).Infof("Session [%s] 's running [id=%d, file=%s] has done [stdout err]", sid, runningId, filePath)
+					logger.Debugf("Session [%s] 's running [id=%d, file=%s] has done [stdout err]", sid, runningId, filePath)
 
 					if nil != wsChannel {
 						channelRet["cmd"] = "run-done"
 						channelRet["output"] = buf
 						err := wsChannel.WriteJSON(&channelRet)
 						if nil != err {
-							glog.Error(err)
+							logger.Error(err)
 							break
 						}
 
@@ -191,7 +194,7 @@ func RunHandler(w http.ResponseWriter, r *http.Request) {
 						channelRet["output"] = buf
 						err := wsChannel.WriteJSON(&channelRet)
 						if nil != err {
-							glog.Error(err)
+							logger.Error(err)
 							break
 						}
 
@@ -216,13 +219,13 @@ func RunHandler(w http.ResponseWriter, r *http.Request) {
 				// remove the exited process from user process set
 				processes.remove(wSession, cmd.Process)
 
-				glog.V(5).Infof("Session [%s] 's running [id=%d, file=%s] has done [stderr err]", sid, runningId, filePath)
+				logger.Debugf("Session [%s] 's running [id=%d, file=%s] has done [stderr err]", sid, runningId, filePath)
 
 				channelRet["cmd"] = "run-done"
 				channelRet["output"] = "<span class='stderr'>" + buf + "</span>"
 				err := wsChannel.WriteJSON(&channelRet)
 				if nil != err {
-					glog.Error(err)
+					logger.Error(err)
 					break
 				}
 
@@ -234,7 +237,7 @@ func RunHandler(w http.ResponseWriter, r *http.Request) {
 				channelRet["output"] = "<span class='stderr'>" + buf + "</span>"
 				err := wsChannel.WriteJSON(&channelRet)
 				if nil != err {
-					glog.Error(err)
+					logger.Error(err)
 					break
 				}
 
@@ -261,7 +264,7 @@ func BuildHandler(w http.ResponseWriter, r *http.Request) {
 	var args map[string]interface{}
 
 	if err := json.NewDecoder(r.Body).Decode(&args); err != nil {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -275,7 +278,7 @@ func BuildHandler(w http.ResponseWriter, r *http.Request) {
 	fout, err := os.Create(filePath)
 
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -286,7 +289,7 @@ func BuildHandler(w http.ResponseWriter, r *http.Request) {
 	fout.WriteString(code)
 
 	if err := fout.Close(); nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -303,13 +306,13 @@ func BuildHandler(w http.ResponseWriter, r *http.Request) {
 	setCmdEnv(cmd, username)
 
 	executable := filepath.Base(curDir) + suffix
-	glog.V(5).Infof("go build for [%s]", executable)
+	logger.Debugf("go build for [%s]", executable)
 
 	executable = filepath.Join(curDir, executable)
 
 	stdout, err := cmd.StdoutPipe()
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -317,7 +320,7 @@ func BuildHandler(w http.ResponseWriter, r *http.Request) {
 
 	stderr, err := cmd.StderrPipe()
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -339,7 +342,7 @@ func BuildHandler(w http.ResponseWriter, r *http.Request) {
 
 		err := wsChannel.WriteJSON(&channelRet)
 		if nil != err {
-			glog.Error(err)
+			logger.Error(err)
 			return
 		}
 
@@ -349,7 +352,7 @@ func BuildHandler(w http.ResponseWriter, r *http.Request) {
 	reader := bufio.NewReader(io.MultiReader(stdout, stderr))
 
 	if err := cmd.Start(); nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -359,7 +362,7 @@ func BuildHandler(w http.ResponseWriter, r *http.Request) {
 		defer util.Recover()
 		defer cmd.Wait()
 
-		glog.V(5).Infof("Session [%s] is building [id=%d, dir=%s]", sid, runningId, curDir)
+		logger.Debugf("Session [%s] is building [id=%d, dir=%s]", sid, runningId, curDir)
 
 		// read all
 		buf, _ := ioutil.ReadAll(reader)
@@ -380,7 +383,7 @@ func BuildHandler(w http.ResponseWriter, r *http.Request) {
 
 				out, _ := cmd.CombinedOutput()
 				if len(out) > 0 {
-					glog.Warning(string(out))
+					logger.Warn(string(out))
 				}
 			}()
 		} else { // build error
@@ -438,7 +441,7 @@ func BuildHandler(w http.ResponseWriter, r *http.Request) {
 				}
 
 				lint := &Lint{
-					File:     filepath.Join(curDir,file),
+					File:     filepath.Join(curDir, file),
 					LineNo:   lineNo - 1,
 					Severity: lintSeverityError,
 					Msg:      msg,
@@ -451,12 +454,12 @@ func BuildHandler(w http.ResponseWriter, r *http.Request) {
 		}
 
 		if nil != session.OutputWS[sid] {
-			glog.V(5).Infof("Session [%s] 's build [id=%d, dir=%s] has done", sid, runningId, curDir)
+			logger.Debugf("Session [%s] 's build [id=%d, dir=%s] has done", sid, runningId, curDir)
 
 			wsChannel := session.OutputWS[sid]
 			err := wsChannel.WriteJSON(&channelRet)
 			if nil != err {
-				glog.Error(err)
+				logger.Error(err)
 			}
 
 			wsChannel.Refresh()
@@ -520,7 +523,7 @@ func GoTestHandler(w http.ResponseWriter, r *http.Request) {
 	var args map[string]interface{}
 
 	if err := json.NewDecoder(r.Body).Decode(&args); err != nil {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -538,7 +541,7 @@ func GoTestHandler(w http.ResponseWriter, r *http.Request) {
 
 	stdout, err := cmd.StdoutPipe()
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -546,7 +549,7 @@ func GoTestHandler(w http.ResponseWriter, r *http.Request) {
 
 	stderr, err := cmd.StderrPipe()
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -568,7 +571,7 @@ func GoTestHandler(w http.ResponseWriter, r *http.Request) {
 
 		err := wsChannel.WriteJSON(&channelRet)
 		if nil != err {
-			glog.Error(err)
+			logger.Error(err)
 			return
 		}
 
@@ -578,7 +581,7 @@ func GoTestHandler(w http.ResponseWriter, r *http.Request) {
 	reader := bufio.NewReader(io.MultiReader(stdout, stderr))
 
 	if err := cmd.Start(); nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -587,7 +590,7 @@ func GoTestHandler(w http.ResponseWriter, r *http.Request) {
 	go func(runningId int) {
 		defer util.Recover()
 
-		glog.V(5).Infof("Session [%s] is running [go test] [runningId=%d]", sid, runningId)
+		logger.Debugf("Session [%s] is running [go test] [runningId=%d]", sid, runningId)
 
 		channelRet := map[string]interface{}{}
 		channelRet["cmd"] = "go test"
@@ -599,11 +602,11 @@ func GoTestHandler(w http.ResponseWriter, r *http.Request) {
 		cmd.Wait()
 
 		if !cmd.ProcessState.Success() {
-			glog.V(5).Infof("Session [%s] 's running [go test] [runningId=%d] has done (with error)", sid, runningId)
+			logger.Debugf("Session [%s] 's running [go test] [runningId=%d] has done (with error)", sid, runningId)
 
 			channelRet["output"] = "<span class='test-error'>" + i18n.Get(locale, "test-error").(string) + "</span>\n" + string(buf)
 		} else {
-			glog.V(5).Infof("Session [%s] 's running [go test] [runningId=%d] has done", sid, runningId)
+			logger.Debugf("Session [%s] 's running [go test] [runningId=%d] has done", sid, runningId)
 
 			channelRet["output"] = "<span class='test-succ'>" + i18n.Get(locale, "test-succ").(string) + "</span>\n" + string(buf)
 		}
@@ -613,7 +616,7 @@ func GoTestHandler(w http.ResponseWriter, r *http.Request) {
 
 			err := wsChannel.WriteJSON(&channelRet)
 			if nil != err {
-				glog.Error(err)
+				logger.Error(err)
 			}
 
 			wsChannel.Refresh()
@@ -638,7 +641,7 @@ func GoInstallHandler(w http.ResponseWriter, r *http.Request) {
 	var args map[string]interface{}
 
 	if err := json.NewDecoder(r.Body).Decode(&args); err != nil {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -654,11 +657,11 @@ func GoInstallHandler(w http.ResponseWriter, r *http.Request) {
 
 	setCmdEnv(cmd, username)
 
-	glog.V(5).Infof("go install %s", curDir)
+	logger.Debugf("go install %s", curDir)
 
 	stdout, err := cmd.StdoutPipe()
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -666,7 +669,7 @@ func GoInstallHandler(w http.ResponseWriter, r *http.Request) {
 
 	stderr, err := cmd.StderrPipe()
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -688,7 +691,7 @@ func GoInstallHandler(w http.ResponseWriter, r *http.Request) {
 
 		err := wsChannel.WriteJSON(&channelRet)
 		if nil != err {
-			glog.Error(err)
+			logger.Error(err)
 			return
 		}
 
@@ -698,7 +701,7 @@ func GoInstallHandler(w http.ResponseWriter, r *http.Request) {
 	reader := bufio.NewReader(io.MultiReader(stdout, stderr))
 
 	if err := cmd.Start(); nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -708,7 +711,7 @@ func GoInstallHandler(w http.ResponseWriter, r *http.Request) {
 		defer util.Recover()
 		defer cmd.Wait()
 
-		glog.V(5).Infof("Session [%s] is running [go install] [id=%d, dir=%s]", sid, runningId, curDir)
+		logger.Debugf("Session [%s] is running [go install] [id=%d, dir=%s]", sid, runningId, curDir)
 
 		// read all
 		buf, _ := ioutil.ReadAll(reader)
@@ -772,12 +775,12 @@ func GoInstallHandler(w http.ResponseWriter, r *http.Request) {
 		}
 
 		if nil != session.OutputWS[sid] {
-			glog.V(5).Infof("Session [%s] 's running [go install] [id=%d, dir=%s] has done", sid, runningId, curDir)
+			logger.Debugf("Session [%s] 's running [go install] [id=%d, dir=%s] has done", sid, runningId, curDir)
 
 			wsChannel := session.OutputWS[sid]
 			err := wsChannel.WriteJSON(&channelRet)
 			if nil != err {
-				glog.Error(err)
+				logger.Error(err)
 			}
 
 			wsChannel.Refresh()
@@ -803,7 +806,7 @@ func GoGetHandler(w http.ResponseWriter, r *http.Request) {
 	var args map[string]interface{}
 
 	if err := json.NewDecoder(r.Body).Decode(&args); err != nil {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -821,7 +824,7 @@ func GoGetHandler(w http.ResponseWriter, r *http.Request) {
 
 	stdout, err := cmd.StdoutPipe()
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -829,7 +832,7 @@ func GoGetHandler(w http.ResponseWriter, r *http.Request) {
 
 	stderr, err := cmd.StderrPipe()
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -851,7 +854,7 @@ func GoGetHandler(w http.ResponseWriter, r *http.Request) {
 
 		err := wsChannel.WriteJSON(&channelRet)
 		if nil != err {
-			glog.Error(err)
+			logger.Error(err)
 			return
 		}
 
@@ -861,7 +864,7 @@ func GoGetHandler(w http.ResponseWriter, r *http.Request) {
 	reader := bufio.NewReader(io.MultiReader(stdout, stderr))
 
 	if err := cmd.Start(); nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -871,7 +874,7 @@ func GoGetHandler(w http.ResponseWriter, r *http.Request) {
 		defer util.Recover()
 		defer cmd.Wait()
 
-		glog.V(5).Infof("Session [%s] is running [go get] [runningId=%d]", sid, runningId)
+		logger.Debugf("Session [%s] is running [go get] [runningId=%d]", sid, runningId)
 
 		channelRet := map[string]interface{}{}
 		channelRet["cmd"] = "go get"
@@ -880,11 +883,11 @@ func GoGetHandler(w http.ResponseWriter, r *http.Request) {
 		buf, _ := ioutil.ReadAll(reader)
 
 		if 0 != len(buf) {
-			glog.V(5).Infof("Session [%s] 's running [go get] [runningId=%d] has done (with error)", sid, runningId)
+			logger.Debugf("Session [%s] 's running [go get] [runningId=%d] has done (with error)", sid, runningId)
 
 			channelRet["output"] = "<span class='get-error'>" + i18n.Get(locale, "get-error").(string) + "</span>\n" + string(buf)
 		} else {
-			glog.V(5).Infof("Session [%s] 's running [go get] [runningId=%d] has done", sid, runningId)
+			logger.Debugf("Session [%s] 's running [go get] [runningId=%d] has done", sid, runningId)
 
 			channelRet["output"] = "<span class='get-succ'>" + i18n.Get(locale, "get-succ").(string) + "</span>\n"
 
@@ -895,7 +898,7 @@ func GoGetHandler(w http.ResponseWriter, r *http.Request) {
 
 			err := wsChannel.WriteJSON(&channelRet)
 			if nil != err {
-				glog.Error(err)
+				logger.Error(err)
 			}
 
 			wsChannel.Refresh()
@@ -910,7 +913,7 @@ func StopHandler(w http.ResponseWriter, r *http.Request) {
 
 	var args map[string]interface{}
 	if err := json.NewDecoder(r.Body).Decode(&args); err != nil {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
diff --git a/output/processes.go b/output/processes.go
index f25b380..88ec622 100644
--- a/output/processes.go
+++ b/output/processes.go
@@ -19,7 +19,6 @@ import (
 	"sync"
 
 	"github.com/b3log/wide/session"
-	"github.com/golang/glog"
 )
 
 // Type of process set.
@@ -47,7 +46,7 @@ func (procs *procs) add(wSession *session.WideSession, proc *os.Process) {
 	// bind process with wide session
 	wSession.SetProcesses(userProcesses)
 
-	glog.V(5).Infof("Session [%s] has [%d] processes", sid, len((*procs)[sid]))
+	logger.Debugf("Session [%s] has [%d] processes", sid, len((*procs)[sid]))
 }
 
 // remove removes the specified process from the user process set.
@@ -68,7 +67,7 @@ func (procs *procs) remove(wSession *session.WideSession, proc *os.Process) {
 			// bind process with wide session
 			wSession.SetProcesses(newProcesses)
 
-			glog.V(5).Infof("Session [%s] has [%d] processes", sid, len((*procs)[sid]))
+			logger.Debugf("Session [%s] has [%d] processes", sid, len((*procs)[sid]))
 
 			return
 		}
@@ -87,7 +86,7 @@ func (procs *procs) kill(wSession *session.WideSession, pid int) {
 	for i, p := range userProcesses {
 		if p.Pid == pid {
 			if err := p.Kill(); nil != err {
-				glog.Error("Kill a process [pid=%d] of session [%s] failed [error=%v]", pid, sid, err)
+				logger.Error("Kill a process [pid=%d] of session [%s] failed [error=%v]", pid, sid, err)
 			} else {
 				var newProcesses []*os.Process
 
@@ -97,7 +96,7 @@ func (procs *procs) kill(wSession *session.WideSession, pid int) {
 				// bind process with wide session
 				wSession.SetProcesses(newProcesses)
 
-				glog.V(5).Infof("Killed a process [pid=%d] of session [%s]", pid, sid)
+				logger.Debugf("Killed a process [pid=%d] of session [%s]", pid, sid)
 			}
 
 			return
diff --git a/session/sessions.go b/session/sessions.go
index 52697ab..594b2d5 100644
--- a/session/sessions.go
+++ b/session/sessions.go
@@ -33,8 +33,8 @@ import (
 
 	"github.com/b3log/wide/conf"
 	"github.com/b3log/wide/event"
+	"github.com/b3log/wide/log"
 	"github.com/b3log/wide/util"
-	"github.com/golang/glog"
 	"github.com/gorilla/sessions"
 	"github.com/gorilla/websocket"
 )
@@ -44,6 +44,9 @@ const (
 	sessionStateClosed // (not used so far)
 )
 
+// Logger.
+var logger = log.NewLogger(os.Stdout)
+
 var (
 	// SessionWS holds all session channels. <sid, *util.WSChannel>
 	SessionWS = map[string]*util.WSChannel{}
@@ -97,7 +100,7 @@ func FixedTimeRelease() {
 
 			for _, s := range WideSessions {
 				if s.Updated.Before(threshold) {
-					glog.V(3).Infof("Removes a invalid session [%s], user [%s]", s.ID, s.Username)
+					logger.Debugf("Removes a invalid session [%s], user [%s]", s.ID, s.Username)
 
 					WideSessions.Remove(s.ID)
 				}
@@ -151,7 +154,7 @@ func FixedTimeReport() {
 				buf.WriteString("    " + t.report() + "\n")
 			}
 
-			glog.Info(buf.String())
+			logger.Info(buf.String())
 		}
 	}()
 }
@@ -174,7 +177,7 @@ func WSHandler(w http.ResponseWriter, r *http.Request) {
 
 		wSession = WideSessions.New(httpSession, sid)
 
-		glog.Infof("Created a wide session [%s] for websocket reconnecting, user [%s]", sid, wSession.Username)
+		logger.Infof("Created a wide session [%s] for websocket reconnecting, user [%s]", sid, wSession.Username)
 	}
 
 	conn, _ := websocket.Upgrade(w, r, nil, 1024, 1024)
@@ -188,13 +191,13 @@ func WSHandler(w http.ResponseWriter, r *http.Request) {
 
 	SessionWS[sid] = &wsChan
 
-	glog.V(4).Infof("Open a new [Session Channel] with session [%s], %d", sid, len(SessionWS))
+	logger.Debugf("Open a new [Session Channel] with session [%s], %d", sid, len(SessionWS))
 
 	input := map[string]interface{}{}
 
 	for {
 		if err := wsChan.ReadJSON(&input); err != nil {
-			glog.V(5).Infof("[Session Channel] of session [%s] disconnected, releases all resources with it, user [%s]",
+			logger.Debugf("[Session Channel] of session [%s] disconnected, releases all resources with it, user [%s]",
 				sid, wSession.Username)
 
 			WideSessions.Remove(sid)
@@ -205,7 +208,7 @@ func WSHandler(w http.ResponseWriter, r *http.Request) {
 		ret = map[string]interface{}{"output": "", "cmd": "session-output"}
 
 		if err := wsChan.WriteJSON(&ret); err != nil {
-			glog.Error("Session WS ERROR: " + err.Error())
+			logger.Error("Session WS ERROR: " + err.Error())
 
 			return
 		}
@@ -225,7 +228,7 @@ func SaveContent(w http.ResponseWriter, r *http.Request) {
 	}{}
 
 	if err := json.NewDecoder(r.Body).Decode(&args); err != nil {
-		glog.Error(err)
+		logger.Error(err)
 		data["succ"] = false
 
 		return
@@ -326,9 +329,9 @@ func (sessions *wSessions) Remove(sid string) {
 			// kill processes
 			for _, p := range s.Processes {
 				if err := p.Kill(); nil != err {
-					glog.Errorf("Can't kill process [%d] of session [%s], user [%s]", p.Pid, sid, s.Username)
+					logger.Errorf("Can't kill process [%d] of session [%s], user [%s]", p.Pid, sid, s.Username)
 				} else {
-					glog.V(3).Infof("Killed a process [%d] of session [%s], user [%s]", p.Pid, sid, s.Username)
+					logger.Debugf("Killed a process [%d] of session [%s], user [%s]", p.Pid, sid, s.Username)
 				}
 			}
 
@@ -355,7 +358,7 @@ func (sessions *wSessions) Remove(sid string) {
 				}
 			}
 
-			glog.V(5).Infof("Removed a session [%s] of user [%s], it has [%d] sessions currently", sid, s.Username, cnt)
+			logger.Debugf("Removed a session [%s] of user [%s], it has [%d] sessions currently", sid, s.Username, cnt)
 
 			return
 		}
diff --git a/session/users.go b/session/users.go
index 70c6d9f..cd3e7c2 100644
--- a/session/users.go
+++ b/session/users.go
@@ -28,7 +28,6 @@ import (
 	"github.com/b3log/wide/conf"
 	"github.com/b3log/wide/i18n"
 	"github.com/b3log/wide/util"
-	"github.com/golang/glog"
 )
 
 const (
@@ -71,7 +70,7 @@ func PreferenceHandler(w http.ResponseWriter, r *http.Request) {
 		t, err := template.ParseFiles("views/preference.html")
 
 		if nil != err {
-			glog.Error(err)
+			logger.Error(err)
 			http.Error(w, err.Error(), 500)
 
 			return
@@ -106,7 +105,7 @@ func PreferenceHandler(w http.ResponseWriter, r *http.Request) {
 	}{}
 
 	if err := json.NewDecoder(r.Body).Decode(&args); err != nil {
-		glog.Error(err)
+		logger.Error(err)
 		succ = false
 
 		return
@@ -142,7 +141,7 @@ func LoginHandler(w http.ResponseWriter, r *http.Request) {
 		t, err := template.ParseFiles("views/login.html")
 
 		if nil != err {
-			glog.Error(err)
+			logger.Error(err)
 			http.Error(w, err.Error(), 500)
 
 			return
@@ -165,7 +164,7 @@ func LoginHandler(w http.ResponseWriter, r *http.Request) {
 	}{}
 
 	if err := json.NewDecoder(r.Body).Decode(&args); err != nil {
-		glog.Error(err)
+		logger.Error(err)
 		succ = false
 
 		return
@@ -194,7 +193,7 @@ func LoginHandler(w http.ResponseWriter, r *http.Request) {
 	}
 	httpSession.Save(r, w)
 
-	glog.Infof("Created a HTTP session [%s] for user [%s]", httpSession.Values["id"].(string), args.Username)
+	logger.Infof("Created a HTTP session [%s] for user [%s]", httpSession.Values["id"].(string), args.Username)
 }
 
 // LogoutHandler handles request of user logout (exit).
@@ -223,7 +222,7 @@ func SignUpUser(w http.ResponseWriter, r *http.Request) {
 		t, err := template.ParseFiles("views/sign_up.html")
 
 		if nil != err {
-			glog.Error(err)
+			logger.Error(err)
 			http.Error(w, err.Error(), 500)
 
 			return
@@ -243,7 +242,7 @@ func SignUpUser(w http.ResponseWriter, r *http.Request) {
 	var args map[string]interface{}
 
 	if err := json.NewDecoder(r.Body).Decode(&args); err != nil {
-		glog.Error(err)
+		logger.Error(err)
 		succ = false
 
 		return
@@ -298,7 +297,7 @@ func addUser(username, password, email string) string {
 	http.Handle("/workspace/"+username+"/",
 		http.StripPrefix("/workspace/"+username+"/", http.FileServer(http.Dir(newUser.GetWorkspace()))))
 
-	glog.Infof("Created a user [%s]", username)
+	logger.Infof("Created a user [%s]", username)
 
 	return userCreated
 }
@@ -307,14 +306,14 @@ func addUser(username, password, email string) string {
 func helloWorld(workspace string) {
 	dir := workspace + conf.PathSeparator + "src" + conf.PathSeparator + "hello"
 	if err := os.MkdirAll(dir, 0755); nil != err {
-		glog.Error(err)
+		logger.Error(err)
 
 		return
 	}
 
 	fout, err := os.Create(dir + conf.PathSeparator + "main.go")
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 
 		os.Exit(-1)
 	}
diff --git a/shell/shells.go b/shell/shells.go
index 8042a30..a0a6a98 100644
--- a/shell/shells.go
+++ b/shell/shells.go
@@ -28,9 +28,9 @@ import (
 
 	"github.com/b3log/wide/conf"
 	"github.com/b3log/wide/i18n"
+	"github.com/b3log/wide/log"
 	"github.com/b3log/wide/session"
 	"github.com/b3log/wide/util"
-	"github.com/golang/glog"
 	"github.com/gorilla/websocket"
 )
 
@@ -39,6 +39,9 @@ import (
 // <sid, *util.WSChannel>>
 var ShellWS = map[string]*util.WSChannel{}
 
+// Logger.
+var logger = log.NewLogger(os.Stdout)
+
 // IndexHandler handles request of Shell index.
 func IndexHandler(w http.ResponseWriter, r *http.Request) {
 	httpSession, _ := session.HTTPSession.Get(r, "wide-session")
@@ -67,12 +70,12 @@ func IndexHandler(w http.ResponseWriter, r *http.Request) {
 
 	wideSessions := session.WideSessions.GetByUsername(username)
 
-	glog.V(3).Infof("User [%s] has [%d] sessions", username, len(wideSessions))
+	logger.Debugf("User [%s] has [%d] sessions", username, len(wideSessions))
 
 	t, err := template.ParseFiles("views/shell.html")
 
 	if nil != err {
-		glog.Error(err)
+		logger.Error(err)
 		http.Error(w, err.Error(), 500)
 
 		return
@@ -104,13 +107,13 @@ func WSHandler(w http.ResponseWriter, r *http.Request) {
 
 	ShellWS[sid] = &wsChan
 
-	glog.V(4).Infof("Open a new [Shell] with session [%s], %d", sid, len(ShellWS))
+	logger.Debugf("Open a new [Shell] with session [%s], %d", sid, len(ShellWS))
 
 	input := map[string]interface{}{}
 
 	for {
 		if err := wsChan.ReadJSON(&input); err != nil {
-			glog.Error("Shell WS ERROR: " + err.Error())
+			logger.Error("Shell WS ERROR: " + err.Error())
 
 			return
 		}
@@ -139,7 +142,7 @@ func WSHandler(w http.ResponseWriter, r *http.Request) {
 		ret = map[string]interface{}{"output": output, "cmd": "shell-output"}
 
 		if err := wsChan.WriteJSON(&ret); err != nil {
-			glog.Error("Shell WS ERROR: " + err.Error())
+			logger.Error("Shell WS ERROR: " + err.Error())
 			return
 		}
 
diff --git a/util/file.go b/util/file.go
index 6330677..13eb510 100644
--- a/util/file.go
+++ b/util/file.go
@@ -1,11 +1,11 @@
 // Copyright (c) 2014, B3log
-// 
+//
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
-// 
+//
 //     http://www.apache.org/licenses/LICENSE-2.0
-// 
+//
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -18,9 +18,12 @@ import (
 	"os"
 	"strings"
 
-	"github.com/golang/glog"
+	"github.com/b3log/wide/log"
 )
 
+// Logger.
+var fileLogger = log.NewLogger(os.Stdout)
+
 type myfile struct{}
 
 // File utilities.
@@ -70,7 +73,7 @@ func (*myfile) IsImg(extension string) bool {
 func (*myfile) IsDir(path string) bool {
 	fio, err := os.Lstat(path)
 	if nil != err {
-		glog.Warningf("Determines whether [%s] is a directory failed: [%v]", path, err)
+		fileLogger.Warnf("Determines whether [%s] is a directory failed: [%v]", path, err)
 
 		return false
 	}
diff --git a/util/panic.go b/util/panic.go
index 4dbf1e9..f7562c5 100644
--- a/util/panic.go
+++ b/util/panic.go
@@ -15,14 +15,18 @@
 package util
 
 import (
+	"os"
 	"runtime/debug"
 
-	"github.com/golang/glog"
+	"github.com/b3log/wide/log"
 )
 
+// Logger.
+var logger = log.NewLogger(os.Stdout)
+
 // Recover recovers a panic.
 func Recover() {
 	if re := recover(); nil != re {
-		glog.Errorf("PANIC RECOVERED:\n %v, %s", re, debug.Stack())
+		logger.Errorf("PANIC RECOVERED:\n %v, %s", re, debug.Stack())
 	}
 }
diff --git a/util/ret.go b/util/ret.go
index 4e74ddb..9936fc6 100644
--- a/util/ret.go
+++ b/util/ret.go
@@ -18,17 +18,21 @@ import (
 	"compress/gzip"
 	"encoding/json"
 	"net/http"
+	"os"
 
-	"github.com/golang/glog"
+	"github.com/b3log/wide/log"
 )
 
+// Logger.
+var retLogger = log.NewLogger(os.Stdout)
+
 // RetJSON writes HTTP response with "Content-Type, application/json".
 func RetJSON(w http.ResponseWriter, r *http.Request, res map[string]interface{}) {
 	w.Header().Set("Content-Type", "application/json")
 
 	data, err := json.Marshal(res)
 	if err != nil {
-		glog.Error(err)
+		retLogger.Error(err)
 		return
 	}
 
@@ -43,13 +47,13 @@ func RetGzJSON(w http.ResponseWriter, r *http.Request, res map[string]interface{
 	gz := gzip.NewWriter(w)
 	err := json.NewEncoder(gz).Encode(res)
 	if nil != err {
-		glog.Error(err)
+		retLogger.Error(err)
 		return
 	}
 
 	err = gz.Close()
 	if nil != err {
-		glog.Error(err)
+		retLogger.Error(err)
 
 		return
 	}