[UPDATE: There is a newer version of CopyFS available]
CopyFS 1.3M is a non-official branch of the CopyFS filesystem for FUSE. v1.3M should be considered an "advanced beta". As it is a FUSE filesystem, faults in the filesystem cannot cause a kernel panic and closed-file dataloss is nearly impossible.
The current CopyFS development is stalled, although the main developer is planning on moving to a shared development environment in the near future. I expect to be adding several more features to CopyFS, however I wanted to get this out in the interim.
CopyFS 1.3M adds the following on top of CopyFS 1.0:
- Text Diffs: Allows for the display of differences between different versions of text files.
- Interversion grep: Allows for matching a Perl regexp against every version of a text file.
- Version purging: Allows for the deletion of all versions of a file.
- Version culling: Allows for the deletion of an arbitrary number of "oldest versions" of a file.
CopyFS M-Branch: http://mattwork.potsdam.edu/projects/copyfs/
FUSE: http://fuse.sf.net/ (FUSE is built into the stock linux kernel as of version 2.6.14. Distro support may vary).