CodeKit

CodeKit automatically compiles Less, Sass, Stylus & CoffeeScript files. It effortlessly combines, minifies and error-checks Javascript. It even optimizes images, auto-reloads your browser and lets you use the same files across many projects. And that’s just the first paragraph.

A fantastic app for developers and designers alike, currently in beta. If you like making your life easier, and happen to use an Apple Computer, you should go get this now. And then, when it’s available on the App Store, you should buy it.

If you just care about compiling .less files on your Mac, you should check out LESS.app, developed by the same guy.