SourceTree - Mac and Windows client for Mercurial and Git.
openDesktop.org - The website openDesktop.
GitKraken - The intuitive, fast, and beautiful cross-platform Git client.
SourceForge - The Complete Open-Source and Business Software Platform.
GitLab - Create, review and deploy code together with GitLab open source git repo management software | GitLab
Freecode - Freecode (formerly known as Freshmeat) is one of the legit open source development platforms that will be the key for developers and programmers to have a streamlined process via having enhanced collaboration and coding leverages.