writes "As a developer and sysadmin, the benefits of revision control systems are clear. It only seems natural that a simpler, transparent approach to versioning files on a regular file system would be a net win. There's ext3cow and Wayback FS, and possibly some fuse-based projects, but each is either dead, immature or just not applicable. So what happened to the promise of versioning file systems? Hasn't everyone lost a file to a bad rm command? Hasn't everyone wished they could see a revision of a file in the past? What's the hold up?"