Its source code can be checked out from here, or you can download a tarball from here.
Here is the project's documentation
Very brief comparison with rsync -- see also this comparison.
Specify files to backup with GNU or BSD find, EG "find / -xdev -print0 | backshift --backup", analogous to cpio
Extract files by running "backshift --produce-tar | tar xvfp -" (the tarball is assembled from deduplicated, compressed chunks on the fly)
Perform remote restores by running "backshift --produce-tar | ssh email@example.com tar xvfp -".
Backshift is not just another tar frontend. Saved data
is stored in an open but created-for-the-purpose, highly compressed format
that can be assembled into a tar archive to stdout on request.
You can e-mail the author with questions or comments: