High Quality Content by WIKIPEDIA articles! The AtheOS file system (AFS) was originally used in the AtheOS operating system, and is now a part of the Syllable operating system. AFS started with exactly the same data structures as the Be File System, BFS, and extended its feature set in many ways. As such, AFS is a 64-bit journaled file system with support for file attributes. File indexing and soft deletions are also partially supported.