Winky is a project mainly written in Java, it's free.
Minecraft Server Wrapper for Real time World Backups using Git
CURRENTLY UNSTABLE - NOT RECOMMENDED FOR LIVE MINECRAFT SERVERS
Why save the entire world when you can just save the changes.
If no [world] is specified with the commands then the level-name in the server.properties is used.
git-commit [world] - Commits a world to the repository.
git-log [world] - List all commits for the given world.
git-reset [world] [id] - Will shutdown the server, reset to a previous commit, and then start the server.