Mimosa will compile your CoffeeScript and Iced CoffeeScript (each w/ source maps), Coco, LiveScript and TypeScript. We'll make more, just ask.
Stylus w/nib. SASS (via Ruby or node) w/Compass. LESS. Mimosa won't bother compiling your partials individually, but when your partials change it'll compile whichever files at the root of your CSS tree need compiling.
Dust. Handlebars. Emblem. Hogan. Underscore. LoDash. Jade. ECO. EJS. Ractive. Just HTML. Mimosa will pre-compile all of your templates. Not using one of these? Request your favorite be added.
Plain JS, Plain CSS, no templates? You're a classic and Mimosa's cool with that. Files that don't need compiling will just be copied, but they'll still get the royal treatment, including linting and RequireJS verification.
Mimosa will keep track of your dependency graph and alert you right away if you've mis-typed a path, referred to something that doesn't exist, or have a circular dependency. It will also keep tabs on your shims, maps and plugin paths.
If you use RequireJS, you probably know about the optimizer. With the tick of a flag Mimosa will run the optimizer on every successful JavaScript compile or copy. And you won't need to configure a thing.
Using an external Mimosa module, you can code using the CommonJS format with your AMD/RequireJS application.
Another external module can be plugged in to give you browserify support, not only letting you code your app using CommonJS, but also letting you bundle node.js code for the browser.