SCM-Manager!

GitLab is a on-premise or hosted Git repository management tool. It also includes code reviews, issue tracking, wikis, and continuous integration.

GitPrep is a GitHub clone. You can install portable Github system into Unix/Linux. You can create users and repositories without limitation. This is free software.

Gitblit is an open-source, pure Java stack for managing, viewing, and serving Git repositories.It's designed primarily as a tool for small workgroups who want to host centralized repositories.

Gitea is a community managed fork of Gogs, lightweight code hosting solution written in Go and published under the MIT license. The code of Gitea is currently hosted on GitHub.

https://stackoverflow.com/questions/8446218/how-to-see-an-html-page-on-github-as-a-normal-rendered-html-page-to-see-preview .... read this to see FAQs relating to it