hello.js

var getName = require('name').getName;

exports.hello = function() {
    return "Hello " + getName();
};

index.html

<script type="text/javascript" src="/js/inject.js"></script>
<script type="text/javascript">
  require.setModuleRoot("http://example.com/js/modules");
  require.run("program");
</script>

index_before.html

<script type="text/javascript" src="/js/modules/name.js"></script>
<script type="text/javascript" src="/js/modules/hello.js"></script>
<script type="text/javascript" src="/js/modules/program.js"></script>

name.js

exports.getName = function() {
    return prompt("What's your name?");
};

program.js

var hello = require('hello').hello;

alert(hello());

@Serpenthelm: open up the console in your browser and see if there are any JS errors. My guess is that your module root isn't being set correctly. For example, if you are testing this code by opening up http://localhost:3000/index.html in your browser, you'll need to update the code to require.setModuleRoot("http://localhost:3000/js/modules");.

Ok, now it works. I had to rename a folder.

However, I can't get this lib to work offline (without a server).
I'm using Firefox+Firebug, I get no error, just this line
Porthole: Using built-in browser support

Then nothing. No error, no alert.

@Serpenthelm: I believe Inject uses XHR to fetch JS files, so you need a valid domain. This means running locally, without a server, won't work, since a file:/// path is probably not going to be recognized as a valid domain. @jakobo could comment more, but I think you'll need to fire up some sort of server (e.g. apache) to test so you can use localhost as a domain.