Ohloh Project Analysis
Aufs is an implementation of the Unionfs file system, which allows layering multiple file systems over each other to form a single directory tree. One of the most useful applications is mounting a read-write layer over another file system to get a read-write file system whose modifications are internally stored in the added layer without touching the original file system. Comes in especially handy when installing bloatware applications that ignore the packaging rules of your distributions and write its files everywhere. Compared to other Unionfs implementations, aufs just works :-) ...