Git Open Source Hosting Server

Bonobo Git Server
Simple git server for Windows. Set up your own self hosted git server on IIS for Windows. Manage users and have full control over your repositories with a nice user friendly graphical interface.
OS: Windows IIS; C#
[http://bonobogitserver.com/]
[https://github.com/jakubgarfield/Bonobo-Git-Server]

GitBucket
GitBucket is the easily installable open-source Github clone written with Scala.
It's provide Github like UI and features such as Git repository hosting via HTTP and SSH, repository viewer, issues, wiki and pull request.
OS: *uix, Mac OS, Windows; Scala;
[https://takezoe.github.io/gitbucket/about/]
[https://github.com/takezoe/gitbucket]

GitLab
Version Control on your Server like GitHub but Open Source.
OS: *uix; Ruby; MySQL PostgreSQL
[https://github.com/gitlabhq/gitlabhq]
[https://about.gitlab.com/]

GitlLite
Hosting git repositories -- Gitolite allows you to setup git hosting on a central server, with very fine-grained access control and many (many!) more powerful features.
OS: *uix; Perl;
[https://github.com/sitaramc/gitolite]