Hmm, I'm not really sure how I'd pull off spriting if More were implemented in javascript. Maybe something with canvas and data uris, but file permissions would be really "fun".

At Stack Exchange, we use dotLESS just fine without having to recompile when we change our .less files. Something Ben Dumke cooked up, an IIS HTTP module I want to say (honestly haven't dug into it).

All that aside, tightening up the REPL is always worthwhile; something I'll through some time at. Maybe a file watcher approach, if I can get it working well cross-platform.