Browseable backups with rdiff-backup and archfs

Note: archfs is now rdiff-backup-fs (see comment below).
In contrast to tools like rsnapshot, which always backs up full versions, rdiff-backup saves only incremental changes in diff files, which takes much less space (and can take a lot of time, too). Because of this it is rather unsuitable for browsing different versions, which is where archfs cuts in.
You need:

• rdiff-backup (Python script, in main repo)
• librsync (from repos, or patched sources, see below)
• Keep (rdiff-backup-frontend, e.g. from the community repos)
• archfs
• fuse-devel
  

librsync seems to be a bit of a zombie (no updates since 2004), but there is a patch from 2006 to fix a serious problem with files greater that 4GB. Run the patch linked in the bug report in the directory above (check the paths in the patch file) the extracted librsync sources:
patch -p0 < 4Gigbug.patch
If you don't have large files, the openSuSE rpm should also work.
archfs: install the tarball and create a mount point, e.g.:
sudo mkdir /media/archives
sudo chown yourname /media/archives
Note: I tried to use a root-owned mount folder with read/execute access, but after the archfs mount all permissions were screwed up. However, the mounted archive is always read-only, so you're on the safe side even if you have full access to the mount point.
Usage: back up with Keep or the rdiff-backup script from command line. With
archfs -r <backuplocation> -m /media/archives/
you will get a browseable archive with version folders listed by date.
Unmount:
sudo umount /media/archives
Use the keep wizard to restore old versions.
OK, OK, the Time Machine has definitely a flashier GUI…