You know, that got me thinking. ZFS will do versioning and, as a filesystem, you'd be keeping your binary data in it anyway. In ZFS, this versioning is implemented as a tree of data blocks, only those blocks that change between versions would be "new". If a block is unchanged, ZFS can exploit shared structure to avoid needless copying.
Right. You can do a lot of things (version control and encryption come to mind) at the filesystem level. A filesystem is a specialized kind of database, anyway, and databases are surprisingly versatile.
If memory serves, you can automatically mount daily snapshots of FreeBSD's standard filesystem. (I'm using OpenBSD, which is slightly different.)
