Bitbucket is a web-based hosting service that supports both Mercurial and Git version control systems. It offers commercial and free accounts. It supports collaboration with unlimited private repos, diff views, CI build integrations, large file storage, pipelines, JIRA and other 3rd party integrations.
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GitHub is a web-based Git or version control repository and Internet hosting service. It offers all of the distributed version control and source code management (SCM) functionality of Git as well as adding its own features. It provides access control and several collaboration features such as bug tracking, feature requests, task management, and wikis for every project.
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Review Board is a feature packed code review tool for multiple SCM systems (like git, bzr, cvs, subversion, etc).
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