Zoiks is a project mainly written in JavaScript, it's free.
Serve your scripts in a single request.
Each request you make to the server is slow. Rather than package your javascript up at build time, why not just ask for several files at once, and bundle them together on the server. One more command line flag and they're minified. Another and the output is cached. And it's in node, so it's faster than you'll ever need.
node server.js -p=<PORT> --debug=<DEBUG LEVEL = debug/warn> /path/to/your/files
then:
request files, separated with commas in the url:
http://localhost:8090/foo.js,bar.js
if you have long path names you can save characters by using brackets:
http://localhost:8090/foo/bar/[baz.js,bong.js]
and you can nest brackets:
http://localhost:8090/foo/bar/[baz.js,bong.js,bing/[bang.js,bot.js]]
You can run arbitrary scripts on your files - so you can retrieve dependancies in js, use sass for your css...