Fossil - Simple, high-reliability, distributed software configuration management
GitHub - Originally founded as a project to simplify sharing code, GitHub has grown into an application used by over a million people to store over two million code repositories, making GitHub the largest code host in the world.
Termlets - "1970's style terminal software, for the rest of us."
GitGud.io - Fast and Free Git hosting site powered by GitLab, hosted by Sapphire.
Mercurial SCM - Mercurial is a free, distributed source control management tool.
Treehouse - Treehouse is an award-winning online platform that teaches people how to code.