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.
BitBucket - Bitbucket is a free code hosting site for Mercurial and Git. Manage your development with a hosted wiki, issue tracker and source code.
GitLab - Create, review and deploy code together with GitLab open source git repo management software | GitLab
CodeHub - CodeHub is the most complete, unofficial, client for GitHub on the iOS platform.
openDesktop.org - The website openDesktop.
git-cola - git-cola is a powerful GUI for git, a distributed revision control system.