Reloader is the fantastic reloader.erl from mochiweb packaged into an application. Use reloader during development to automatically reload modules when they are compiled. It also re-runs tests if the test/0 method is exported.

If you're using rebar (try it, it's great - http://hg.basho.com/rebar/wiki/Home), you can add this to you rebar.config:

{deps, [
  {reloader, "0.1", {git, "http://github.com/bjnortier/reloader.git", "master"}}
}

then:

application:start(reloader).

Otherwise you can build it with:

$./rebar compile

and add to you load path with using your preferred method.