Gugit is a git clone that I wrote to familiarize myself with the inner workings of git. At the moment it only supports a fraction of commands.

• diff
• merge
• init
• commit
• show
• status
• log
• branch
• checkout

• Add three way merge and fast-forward merge.
• Consider using only one diff library, however one nicely outputs diffed lines and other allows for merging.
• Implement index (staging area).
• Cleanup error handling (use utils.check instead of doing to manually).

https://www.leshenko.net/p/ugit/#