I wonder why nobody has yet mentioned rdiff-backup. It combines browsable directories with multiple versions - the version data is stored in a separate rdiff-backup-data subdirectory (one per backup task). One downside is that rdiff-backup causes a lot of network traffic. For that reason I currently use rsync to copy over network, and then I use rdiff-backup locally to create a repository with multiple versions. Another system that we use is rdiffweb. It uses rdiff-backup over network and adds a web interface for clients to browse and restore files or directories. I did not personally set it up, but it seems to work fine. - Jussi