diff --git a/bin/release b/bin/release
index 8f07c2c2..67f92869 100755
--- a/bin/release
+++ b/bin/release
@@ -1,24 +1,65 @@
 #! /bin/bash
 
+set -e
+set -o nounset
+
 # Preparation
 
 ## Get the new version number from the most recent tag
 
-# Sanity checks
+LATEST_TAG=$(git describe --abbrev=0 --match='v*')
+VERSION=${LATEST_TAG#v}
+echo Attempt to build distributables for version $VERSION
+# NB does not check that this tag is on master
+
+echo
+echo == Sanity checks
 
 ## Check that the version doesn't already exist by looking at github
 ## releases
+if curl -sSf https://api.github.com/repos/zettio/weave/releases/$LATEST_TAG 2>/dev/null; then
+    echo Release $LATEST_TAG already exists on GitHub
+    echo https://github.com/zettio/weave/releases/$LATEST_TAG
+    exit 1
+fi
+
+## Clone the repo at the tag and go there
+RELEASE_DIR=releases/$LATEST_TAG
+mkdir -p releases
+git clone -q -b $LATEST_TAG . $RELEASE_DIR
+cd $RELEASE_DIR
 
 ## Check that the top changelog entry is this version
+latest_changelog=$(grep -o "Release v.*" -m1 ./CHANGELOG.md)
+if ! [ `echo "$latest_changelog" | grep -o 'v[^ ]*'` == $LATEST_TAG ]; then
+    echo Latest changelog entry $latest_changelog does not match
+    echo the latest tag $LATEST_TAG
+    exit 1
+fi
 
-# Build and test
+echo Sanity checks OK for releasing tag $LATEST_TAG
 
-# Clone the repo at the tag, inject the version numbers, build
-# distributables (library versions?)
+echo
+echo == Build and test
 
-# Run tests with the distributables, including version check
+## Inject the version numbers and build the distributables
+## (library versions?)
+
+sed -i "/var version = / c\var version = \"$VERSION\"" weaver/main.go
+make
+
+## Run tests with the distributables, including version check
+v=$(./weaver/weaver --version)
+if ! [ "$v" == "weaver $VERSION" ]; then
+    echo Version of distributable "$v" does not match tag $LATEST_TAG
+    exit 1
+fi
+
+make tests
+
+echo Build and tests OK
 
 # Publish
 
-# Either leave the distributables in a directory for the dev to
-# upload, or upload them automatically?
+## Either leave the distributables in a directory for the dev to
+## upload, or upload them automatically?
diff --git a/weaver/main.go b/weaver/main.go
index 177f14ba..c28b9bb9 100644
--- a/weaver/main.go
+++ b/weaver/main.go
@@ -18,6 +18,8 @@ import (
 	"syscall"
 )
 
+var version = "(unreleased version)"
+
 func main() {
 
 	log.SetPrefix(weave.Protocol + " ")
@@ -32,17 +34,19 @@ func main() {
 	runtime.GOMAXPROCS(procs)
 
 	var (
-		ifaceName  string
-		routerName string
-		password   string
-		wait       int
-		debug      bool
-		prof       string
-		peers      []string
-		connLimit  int
-		bufSz      int
+		justVersion bool
+		ifaceName   string
+		routerName  string
+		password    string
+		wait        int
+		debug       bool
+		prof        string
+		peers       []string
+		connLimit   int
+		bufSz       int
 	)
 
+	flag.BoolVar(&justVersion, "version", false, "print version and exit")
 	flag.StringVar(&ifaceName, "iface", "", "name of interface to read from")
 	flag.StringVar(&routerName, "name", "", "name of router (defaults to MAC)")
 	flag.StringVar(&password, "password", "", "network password")
@@ -54,6 +58,11 @@ func main() {
 	flag.Parse()
 	peers = flag.Args()
 
+	if justVersion {
+		io.WriteString(os.Stdout, fmt.Sprintf("weaver %s\n", version))
+		os.Exit(0)
+	}
+
 	options := make(map[string]string)
 	flag.Visit(func(f *flag.Flag) {
 		value := f.Value.String()
@@ -127,6 +136,7 @@ func main() {
 
 func handleHttp(router *weave.Router) {
 	http.HandleFunc("/status", func(w http.ResponseWriter, r *http.Request) {
+		io.WriteString(w, fmt.Sprintln("weaver version", version))
 		io.WriteString(w, router.Status())
 	})
 	http.HandleFunc("/connect", func(w http.ResponseWriter, r *http.Request) {