diff --git a/dev/update_closure_compiler.go b/dev/update_closure_compiler.go
new file mode 100644
index 000000000..8ac60fcc9
--- /dev/null
+++ b/dev/update_closure_compiler.go
@@ -0,0 +1,139 @@
+/*
+Copyright 2013 The Camlistore Authors.
+
+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.
+*/
+
+// The updatelibrary command allows to selectively download
+// from the closure library git repository (at a chosen revision)
+// the resources needed by the Camlistore ui.
+package main
+
+import (
+	"archive/zip"
+	"io"
+	"log"
+	"net/http"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"regexp"
+
+	"camlistore.org/pkg/osutil"
+)
+
+const (
+	compilerDirURL  = "http://closure-compiler.googlecode.com/files/"
+	compilerVersion = "20121212"
+)
+
+var rgxVersion = regexp.MustCompile(`.*Version: (.*) \(revision.*`)
+
+func main() {
+
+	// check JRE presence
+	_, err := exec.LookPath("java")
+	if err != nil {
+		log.Fatal("Didn't find 'java' in $PATH. The Java Runtime Environment is needed to run the closure compiler.\n")
+	}
+
+	camliRootPath, err := osutil.GoPackagePath("camlistore.org")
+	if err != nil {
+		log.Fatal("Package camlistore.org not found in $GOPATH (or $GOPATH not defined).")
+	}
+	destDir := filepath.Join(camliRootPath, "tmp", "closure-compiler")
+	// check if compiler already exists
+	jarFile := filepath.Join(destDir, "compiler.jar")
+	_, err = os.Stat(jarFile)
+	if err == nil {
+		// if compiler exists, check version
+		cmd := exec.Command("java", "-jar", jarFile, "--version", "--help", "2>&1")
+		output, _ := cmd.CombinedOutput()
+		m := rgxVersion.FindStringSubmatch(string(output))
+		if m == nil {
+			log.Fatalf("Could not find compiler version in %q", output)
+		}
+		if m[1] == compilerVersion {
+			log.Printf("compiler already at version %v , nothing to do.", compilerVersion)
+			os.Exit(0)
+		}
+		if err := os.Remove(jarFile); err != nil {
+			log.Fatalf("Could not remove %v: %v", jarFile, err)
+		}
+	} else {
+		if !os.IsNotExist(err) {
+			log.Fatalf("Could not stat %v: %v", jarFile, err)
+		}
+	}
+
+	// otherwise, download compiler
+	log.Printf("Getting closure compiler version %s.\n", compilerVersion)
+	if err := os.MkdirAll(destDir, 0755); err != nil {
+		log.Fatal(err)
+	}
+	if err := os.Chdir(destDir); err != nil {
+		log.Fatal(err)
+	}
+	zipFilename := "compiler-" + compilerVersion + ".zip"
+	compilerURL := compilerDirURL + zipFilename
+	resp, err := http.Get(compilerURL)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer resp.Body.Close()
+	f, err := os.Create(zipFilename)
+	if err != nil {
+		log.Fatal(err)
+	}
+	if _, err := io.Copy(f, resp.Body); err != nil {
+		log.Fatal(err)
+	}
+	if err := f.Close(); err != nil {
+		log.Fatal(err)
+	}
+
+	r, err := zip.OpenReader(zipFilename)
+	if err != nil {
+		log.Fatal(err)
+	}
+	for x, f := range r.File {
+		if f.FileHeader.Name != "compiler.jar" {
+			if x == len(r.File)-1 {
+				log.Fatal("compiler.jar was not found in the zip archive")
+			}
+			continue
+		}
+		rc, err := f.Open()
+		if err != nil {
+			log.Fatal(err)
+		}
+		g, err := os.Create(jarFile)
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer g.Close()
+		if _, err = io.Copy(g, rc); err != nil {
+			log.Fatal(err)
+		}
+		rc.Close()
+		break
+	}
+
+	if err := r.Close(); err != nil {
+		log.Fatal(err)
+	}
+	if err := os.Remove(zipFilename); err != nil {
+		log.Fatal(err)
+	}
+	log.Printf("Success. Installed at %v", jarFile)
+}