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.
Traq - Traq is a PHP powered project manager and issue tracker featuring multiple projects, milestones...
GitLab - Create, review and deploy code together with GitLab open source git repo management software | GitLab
PlayNice.ly - PlayNice.ly is a blazing issue tracking software, making it easy for you developers to find out all the major bugs and errors.
BitBucket - Bitbucket is a free code hosting site for Mercurial and Git. Manage your development with a hosted wiki, issue tracker and source code.
Bugify - Bugify is a simple PHP issue tracker, designed to offer powerful bug tracking capabilities in an easy to use system.