diff --git a/pkg/socket/socket.go b/pkg/socket/socket.go
index 42a351f..e24d21c 100644
--- a/pkg/socket/socket.go
+++ b/pkg/socket/socket.go
@@ -28,6 +28,8 @@
 	"runtime"
 	"strconv"
 	"strings"
+	"sync"
+	"time"
 	"unicode/utf8"
 
 	"code.google.com/p/go.net/websocket"
@@ -40,7 +42,13 @@
 // invoked.
 var Environ func() []string = os.Environ
 
-const msgLimit = 1000 // max number of messages to send per session
+const (
+	// The maximum number of messages to send per session (avoid flooding).
+	msgLimit = 1000
+
+	// Batch messages sent in this interval and send as a single message.
+	msgDelay = 10 * time.Millisecond
+)
 
 // Message is the wire format for the websocket connection to the browser.
 // It is used for both sending output messages and receiving commands, as
@@ -223,7 +231,8 @@
 	if err != nil {
 		m.Body = err.Error()
 	}
-	p.out <- m
+	// Wait for any outstanding reads to finish (potential race here).
+	time.AfterFunc(msgDelay, func() { p.out <- m })
 }
 
 // cmd builds an *exec.Cmd that writes its standard output and error to the
@@ -232,8 +241,8 @@
 	cmd := exec.Command(args[0], args[1:]...)
 	cmd.Dir = dir
 	cmd.Env = Environ()
-	cmd.Stdout = &messageWriter{p.id, "stdout", p.out}
-	cmd.Stderr = &messageWriter{p.id, "stderr", p.out}
+	cmd.Stdout = &messageWriter{id: p.id, kind: "stdout", out: p.out}
+	cmd.Stderr = &messageWriter{id: p.id, kind: "stderr", out: p.out}
 	return cmd
 }
 
@@ -251,13 +260,31 @@
 type messageWriter struct {
 	id, kind string
 	out      chan<- *Message
+
+	mu   sync.Mutex
+	buf  []byte
+	send *time.Timer
 }
 
 func (w *messageWriter) Write(b []byte) (n int, err error) {
-	w.out <- &Message{Id: w.id, Kind: w.kind, Body: safeString(b)}
+	// Buffer writes that occur in a short period to send as one Message.
+	w.mu.Lock()
+	w.buf = append(w.buf, b...)
+	if w.send == nil {
+		w.send = time.AfterFunc(msgDelay, w.sendNow)
+	}
+	w.mu.Unlock()
 	return len(b), nil
 }
 
+func (w *messageWriter) sendNow() {
+	w.mu.Lock()
+	body := safeString(w.buf)
+	w.buf, w.send = nil, nil
+	w.mu.Unlock()
+	w.out <- &Message{Id: w.id, Kind: w.kind, Body: body}
+}
+
 // safeString returns b as a valid UTF-8 string.
 func safeString(b []byte) string {
 	if utf8.Valid(b) {