require brings require to the browser

Node's require() is the de facto javascript dependency statement.

npm is the de facto javascript module manager.

require brings both of them to the browser.

tl;dr

"Just give me some code that runs"

mkdir app; cd app
echo '{ "name":"app" }' > package.json
sudo npm install require
sudo npm install raphael
curl -O https://raw.github.com/gist/975866/little_server.js
curl -O https://raw.github.com/gist/975868/little_client.js
node little_server.js

Now go to http://localhost:8080

Install

sudo npm install -g require

Run

Start dev server

require serve ./example --port 1234 --host localhost

In your HTML:

<script src="//localhost:1234/require/client"></script>

This is like calling require('client') from inside ./example.
Read more on node's require path resolution

Compile

(You'll want to do this before you deploy to production)

require compile ./example/client.js > client.min.js

Use programmatically

In node:

require('require/server').listen(1234)

or mount it on an http server you're already running

var server = http.createServer(function(req, res) { })
require('require/server').mount(server)
server.listen(8080, 'localhost')

or, as connect middleware

connect.createServer(
	connect.static(__dirname + '/example'),
	require('require/server').connect()
)

Compile programmatically:

var compiler = require('require/compiler')
console.log(compiler.compile('./example/client.js'))
console.log(compiler.compileCode('require("./example/client")'))

The compiler supports all the options of https://github.com/mishoo/UglifyJS, e.g.

compiler.compile('./example/client.js', { beautify:true, ascii_only:true })