diff --git a/misc/dashboard/app/app.yaml b/misc/dashboard/app/app.yaml
index 6e19db09c62..47b7d822a39 100644
--- a/misc/dashboard/app/app.yaml
+++ b/misc/dashboard/app/app.yaml
@@ -13,8 +13,8 @@ handlers:
   static_dir: static
 - url: /log/.+
   script: _go_app
-- url: /(|commit|packages|result|tag|todo)
+- url: /(|commit|install|packages|result|tag|todo)
   script: _go_app
-- url: /(init|buildtest|key|_ah/queue/go/delay)
+- url: /(init|buildtest|key|_ah/queue/go/delay|install/cron)
   script: _go_app
   login: admin
diff --git a/misc/dashboard/app/build/build.go b/misc/dashboard/app/build/build.go
index c49fa8bb2af..a7b08321b46 100644
--- a/misc/dashboard/app/build/build.go
+++ b/misc/dashboard/app/build/build.go
@@ -12,6 +12,7 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
+	"strconv"
 	"strings"
 	"time"
 
@@ -27,6 +28,10 @@ type Package struct {
 	Name    string
 	Path    string // (empty for the main Go tree)
 	NextNum int    // Num of the next head Commit
+
+	Installs         int      // All-time total install count
+	InstallsByDay    []string `datastore:",noindex"` // "yyyy-mm-dd,n"
+	InstallsThisWeek int      // Rolling weekly count
 }
 
 func (p *Package) String() string {
@@ -41,6 +46,53 @@ func (p *Package) Key(c appengine.Context) *datastore.Key {
 	return datastore.NewKey(c, "Package", key, 0, nil)
 }
 
+const day = time.Hour * 24
+
+// IncrementInstalls increments the total install count and today's install count.
+// Daily install counts for dates older than 30 days are discarded.
+func (p *Package) IncrementInstalls() {
+	c := p.dayCounts()
+	s := []string{}
+	now := time.Now()
+	for i := 0; i < 30; i++ {
+		d := now.Add(-day * time.Duration(i)).Format("2006-01-02")
+		n := c[d]
+		if i == 0 {
+			n++ // increment today's count
+		}
+		if n > 0 { // no need to store zeroes in the datastore
+			s = append(s, fmt.Sprintf("%s,%d", d, n))
+		}
+	}
+	p.InstallsByDay = s
+	p.Installs++
+	p.UpdateInstallsThisWeek()
+}
+
+// UpdateInstallsThisWeek updates the package's InstallsThisWeek field using data
+// from the InstallsByDay list.
+func (p *Package) UpdateInstallsThisWeek() {
+	c := p.dayCounts()
+	n := 0
+	now := time.Now()
+	for i := 0; i < 7; i++ {
+		d := now.Add(-day * time.Duration(i)).Format("2006-01-02")
+		n += c[d]
+	}
+	p.InstallsThisWeek = n
+}
+
+// dayCounts explodes InstallsByDay into a map of dates to install counts.
+func (p *Package) dayCounts() map[string]int {
+	c := make(map[string]int)
+	for _, d := range p.InstallsByDay {
+		p := strings.SplitN(d, ",", 2)
+		n, _ := strconv.Atoi(p[1])
+		c[p[0]] = n
+	}
+	return c
+}
+
 // LastCommit returns the most recent Commit for this Package.
 func (p *Package) LastCommit(c appengine.Context) (*Commit, error) {
 	var commits []*Commit
diff --git a/misc/dashboard/app/build/pkg.go b/misc/dashboard/app/build/pkg.go
new file mode 100644
index 00000000000..076fafe4fdf
--- /dev/null
+++ b/misc/dashboard/app/build/pkg.go
@@ -0,0 +1,201 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package build
+
+import (
+	"net/http"
+	"regexp"
+	"strings"
+
+	"appengine"
+	"appengine/datastore"
+	"appengine/delay"
+	"appengine/urlfetch"
+)
+
+func init() {
+	http.HandleFunc("/install", installHandler)
+	http.HandleFunc("/install/cron", installCronHandler)
+}
+
+// installHandler serves requests from the go tool to increment the install
+// count for a given package.
+func installHandler(w http.ResponseWriter, r *http.Request) {
+	installLater.Call(appengine.NewContext(r), r.FormValue("packagePath"))
+}
+
+// installCronHandler starts a task to update the weekly install counts for
+// every external package.
+func installCronHandler(w http.ResponseWriter, r *http.Request) {
+	c := appengine.NewContext(r)
+	q := datastore.NewQuery("Package").Filter("Kind=", "external").KeysOnly()
+	for t := q.Run(c); ; {
+		key, err := t.Next(nil)
+		if err == datastore.Done {
+			break
+		} else if err != nil {
+			c.Errorf("%v", err)
+			return
+		}
+		updateWeeklyLater.Call(c, key)
+	}
+}
+
+var (
+	installLater      = delay.Func("install", install)
+	updateWeeklyLater = delay.Func("updateWeekly", updateWeekly)
+)
+
+// install validates the provided package path, increments its install count,
+// and creates the Package record if it doesn't exist.
+func install(c appengine.Context, path string) {
+	if !validPath(c, path) {
+		return
+	}
+	tx := func(c appengine.Context) error {
+		p := &Package{Path: path, Kind: "external"}
+		err := datastore.Get(c, p.Key(c), p)
+		if err != nil && err != datastore.ErrNoSuchEntity {
+			return err
+		}
+		p.IncrementInstalls()
+		_, err = datastore.Put(c, p.Key(c), p)
+		return err
+	}
+	if err := datastore.RunInTransaction(c, tx, nil); err != nil {
+		c.Errorf("install(%q): %v", path, err)
+	}
+}
+
+// updateWeekly updates the weekly count for the specified Package.
+func updateWeekly(c appengine.Context, key *datastore.Key) {
+	tx := func(c appengine.Context) error {
+		p := new(Package)
+		if err := datastore.Get(c, key, p); err != nil {
+			return err
+		}
+		p.UpdateInstallsThisWeek()
+		_, err := datastore.Put(c, key, p)
+		return err
+	}
+	if err := datastore.RunInTransaction(c, tx, nil); err != nil {
+		c.Errorf("updateWeekly: %v", err)
+	}
+}
+
+// validPath validates the specified import path by matching it against the
+// vcsPath regexen and validating its existence by making an HTTP GET request
+// to the remote repository.
+func validPath(c appengine.Context, path string) bool {
+	for _, p := range vcsPaths {
+		if !strings.HasPrefix(path, p.prefix) {
+			continue
+		}
+		m := p.regexp.FindStringSubmatch(path)
+		if m == nil {
+			continue
+		}
+		if p.check == nil {
+			// no check function, so just say OK
+			return true
+		}
+		match := make(map[string]string)
+		for i, name := range p.regexp.SubexpNames() {
+			if name != "" {
+				match[name] = m[i]
+			}
+		}
+		return p.check(c, match)
+	}
+	c.Debugf("validPath(%q): matching vcsPath not found", path)
+	return false
+}
+
+// A vcsPath describes how to convert an import path into a version control
+// system and repository name.
+//
+// This is a cut down and modified version of the data structure from
+// $GOROOT/src/cmd/go/vcs.go.
+type vcsPath struct {
+	prefix string // prefix this description applies to
+	re     string // pattern for import path
+
+	// check should perform an HTTP request to validate the import path
+	check func(c appengine.Context, match map[string]string) bool
+
+	regexp *regexp.Regexp // cached compiled form of re
+}
+
+// vcsPaths lists the known vcs paths.
+//
+// This is a cut down version of the data from $GOROOT/src/cmd/go/vcs.go.
+var vcsPaths = []*vcsPath{
+	// Google Code - new syntax
+	{
+		prefix: "code.google.com/",
+		re:     `^(?P<root>code\.google\.com/p/(?P<project>[a-z0-9\-]+)(\.(?P<subrepo>[a-z0-9\-]+))?)(/[A-Za-z0-9_.\-]+)*$`,
+		check:  googleCodeVCS,
+	},
+
+	// Github
+	{
+		prefix: "github.com/",
+		re:     `^(?P<root>github\.com/[A-Za-z0-9_.\-]+/[A-Za-z0-9_.\-]+)(/[A-Za-z0-9_.\-]+)*$`,
+		check:  checkRoot,
+	},
+
+	// Bitbucket
+	{
+		prefix: "bitbucket.org/",
+		re:     `^(?P<root>bitbucket\.org/(?P<bitname>[A-Za-z0-9_.\-]+/[A-Za-z0-9_.\-]+))(/[A-Za-z0-9_.\-]+)*$`,
+		check:  checkRoot,
+	},
+
+	// Launchpad
+	{
+		prefix: "launchpad.net/",
+		re:     `^(?P<root>launchpad\.net/((?P<project>[A-Za-z0-9_.\-]+)(?P<series>/[A-Za-z0-9_.\-]+)?|~[A-Za-z0-9_.\-]+/(\+junk|[A-Za-z0-9_.\-]+)/[A-Za-z0-9_.\-]+))(/[A-Za-z0-9_.\-]+)*$`,
+		// TODO(adg): write check function for Launchpad
+	},
+}
+
+func init() {
+	// Compile the regular expressions.
+	for i := range vcsPaths {
+		vcsPaths[i].regexp = regexp.MustCompile(vcsPaths[i].re)
+	}
+}
+
+// googleCodeVCS performs an HTTP GET to verify that a Google Code project
+// (and, optionally, a sub-repository) exists.
+func googleCodeVCS(c appengine.Context, match map[string]string) bool {
+	u := "https://code.google.com/p/" + match["project"]
+	if match["subrepo"] != "" {
+		u += "/source/checkout?repo=" + match["subrepo"]
+	}
+	return checkURL(c, u)
+}
+
+// checkRoot performs an HTTP GET to verify that a specific repository root
+// exists (for github and bitbucket both).
+func checkRoot(c appengine.Context, match map[string]string) bool {
+	return checkURL(c, "https://"+match["root"])
+}
+
+// checkURL performs an HTTP GET to the specified URL and returns whether the
+// remote server returned a 2xx response.
+func checkURL(c appengine.Context, u string) bool {
+	client := urlfetch.Client(c)
+	resp, err := client.Get(u)
+	if err != nil {
+		c.Errorf("checkURL(%q): %v", u, err)
+		return false
+	}
+	if resp.StatusCode/100 != 2 {
+		c.Debugf("checkURL(%q): HTTP status: %s", u, resp.Status)
+		return false
+	}
+	return true
+}
diff --git a/misc/dashboard/app/cron.yaml b/misc/dashboard/app/cron.yaml
new file mode 100644
index 00000000000..b54c24cef78
--- /dev/null
+++ b/misc/dashboard/app/cron.yaml
@@ -0,0 +1,4 @@
+cron:
+- description: update rolling package install counts
+  url: /install/cron
+  schedule: every 24 hours