ZipSnap

Ever wished there was an easy way to backup multiple versions of your files, or quickly synchronize them across different computers (even on different operating systems) so that you always work with the most recent copies? ZipSnap can help you with that!
ZipSnap creates archives that are collections of point-in-time snapshots. An archive is just a directory of catalogs (plain text files compressed as ZIP files) and compressed volumes (ZIP files). When a snapshot is added to an archive, a new compressed volume is created, containing only new or modified files and directories. A catalog is used to store information on the snapshots and contents of the archive. Files are automatically numbered with a timestamp. Runs on any OS with the Java Runtime Environment (JRE 6+). ZipSnap is free and open source software written in Java and released under the GNU GPL license (version 3).
MAIN FEATURES:
* ZipSnap creates archives that are collections of point-in-time snapshots. An archive is just a directory of catalogs (plain text files compressed as ZIP files) and compressed volumes (ZIP files).
* Catalogs are written cumulatively, i.e. a later catalog contains all the information from previous catalogs. Therefore, only the latest catalog is needed when adding/restoring snapshots.
* Catalogs and compressed volumes are automatically timestamped as ArchiveName.yyyyMMdd-HHmmss.n, with extensions .txt.zip and .zip respectively, where n is the snapshot number.
* Because ZipSnap never modifies a catalog or compressed volume after it is created, archives can be stored on write-once-only media.
* ZipSnap supports GLOB and REGEX filters for file/directory names, or their full (relative) pathnames.
See http://zipsnap.sourceforge.net / for the latest version, screenshots, documentation, and other information.