Bingo. But keep in mind that Sprockets doesn't have to be used just as a Rack server to compile on the fly, it can also be used to precompile to static files. In fact, you could then combine it with something like the watcher gem, and you now have automatic precompiling whenever you save your source files. In fact, there's the guard-sprockets gem which does all this for you [1].

[1] https://github.com/pferdefleisch/guard-sprockets