I was using Grunt and while and had a pretty awesome config file set up, but I've recently discovered AssetGraph and feel the urge to convert to it!

AssetGraph - https://github.com/One-com/assetgraph AssetGraph Builder - https://github.com/One-com/assetgraph-builder

Edit: There's actually a grunt plugin for it too: https://github.com/Munter/grunt-reduce