If you want to maximize for network effects, it's GitHub. I'm not keen on GitHub issues, and the lack of a mailing list is disappointing as well (which would fu

If you want to maximize for network effects, it's GitHub. I'm not keen on GitHub issues, and the lack of a mailing list is disappointing as well (which would funnel _actual_ social collaboration), but in terms of popularity is still your best bet. By experience, GitLab is not worse and the performance and UI is ok despite the critiques here in HN. I do not find it significantly better to justify the switch though. Issues are similarly watered down, and there's no option for a mailing list. SourceForce's UI is bad, their reputation is tainted, but the functionality is all there. I'm unsure about launchpad. Their project page is confusing for newcomers, but their issue management is much better than github/gitlab. I never contributed to bitbucket enough to comment, and do not host any project there.