Sourcegraph : Sourcegraph Server is a free, self-hosted code search server that integrates with your code host and supports multi-repository, regexp, and diff searc...
gitflow : Git extensions to provide high-level repository operations for Vincent Driessen's branching model.
pre-commit : A framework for managing and maintaining multi-language pre-commit hooks.
Git Extensions is the only graphical user interface for Git that allows you control Git without using the commandline. It comes with a manual and video tutorials to get you started quickly.