diff --git a/main.go b/main.go
index 1c3752f9c..069c6dd65 100644
--- a/main.go
+++ b/main.go
@@ -187,16 +187,26 @@ func main() {
 
 	// GUI
 	if cfg.Options.GUIEnabled && cfg.Options.GUIAddress != "" {
-		host, port, err := net.SplitHostPort(cfg.Options.GUIAddress)
+		addr, err := net.ResolveTCPAddr("tcp", cfg.Options.GUIAddress)
 		if err != nil {
 			warnf("Cannot start GUI on %q: %v", cfg.Options.GUIAddress, err)
 		} else {
-			if len(host) > 0 {
-				infof("Starting web GUI on http://%s", cfg.Options.GUIAddress)
-			} else {
-				infof("Starting web GUI on port %s", port)
+			var hostOpen, hostShow string
+			switch {
+			case addr.IP == nil:
+				hostOpen = "localhost"
+				hostShow = "0.0.0.0"
+			case addr.IP.IsUnspecified():
+				hostOpen = "localhost"
+				hostShow = addr.IP.String()
+			default:
+				hostOpen = addr.IP.String()
+				hostShow = hostOpen
 			}
+
+			infof("Starting web GUI on http://%s:%d/", hostShow, addr.Port)
 			startGUI(cfg.Options.GUIAddress, m)
+			openURL(fmt.Sprintf("http://%s:%d", hostOpen, addr.Port))
 		}
 	}
 
diff --git a/openurl.go b/openurl.go
new file mode 100644
index 000000000..b75c1d385
--- /dev/null
+++ b/openurl.go
@@ -0,0 +1,34 @@
+/*
+Copyright 2011 Google Inc.
+
+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.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package main
+
+import (
+	"os/exec"
+	"runtime"
+)
+
+func openURL(url string) error {
+	if runtime.GOOS == "windows" {
+		return exec.Command("cmd.exe", "/C", "start "+url).Run()
+	}
+
+	if runtime.GOOS == "darwin" {
+		return exec.Command("open", url).Run()
+	}
+
+	return exec.Command("xdg-open", url).Run()
+}