Sonar : Sonar is an open platform to manage code quality.
Diffuse : Diffuse is a small and simple text merge tool written in Python. With Diffuse, you can easily merge, edit, and review changes to your code.
VersionPress : VersionPress is a free and open source version control plugin for WordPress built on Git. You can:
Undo changes
Create staging sites
Merge databases ...
Weblate is a free web-based translation tool with tight Git integration. It features simple and clean user interface, propagation of translations across subprojects, quality checks and automatic linking to source files.