From CVS Checkouts to Pull Requests
SourceForge launched in 1999, built by VA Linux Systems to give open-source projects a common home: bug trackers, mailing lists, and CVS or Subversion repositories under one roof. At its peak in the mid-2000s it hosted hundreds of thousands of projects and was the practical centre of open-source distribution. If you shipped free software, SourceForge was where you put it.
GitHub launched in April 2008, built around Git and a social model that SourceForge had never attempted. Forking, pull requests, and inline code review were native to the interface rather than bolted on. Adoption was rapid among the developers who were already using Git — itself spreading fast after Linus Torvalds had released it in 2005 to manage Linux kernel development. Within two years GitHub had passed one million repositories. By 2011 it reported two million; by 2013, ten million. GitHub's own repository-count milestones record a consistent upward curve through that decade.
SourceForge's decline accelerated after 2013, when its then-owner Dice Holdings introduced "DevShare," a bundled-installer programme that wrapped open-source downloads in adware without maintainer consent. Projects including VLC and GIMP publicly disowned their own SourceForge mirrors and moved archives elsewhere. Dice, which had acquired the platform from Geeknet, later renamed itself DHI Group and sold it on, and the adware programme was eventually discontinued — but the reputational damage had compounded the structural problem. SourceForge's traffic and ownership history illustrates how the platform changed hands and lost ground through that period.
Microsoft acquired GitHub in June 2018 for $7.5 billion, a purchase that concentrated critical open-source infrastructure inside a single commercial entity. The acquisition was controversial: free-software advocates noted that the platform carrying the majority of the world's public code was now owned by the same company that had, decades earlier, described open source as a cancer. The counter-argument — that Microsoft had changed, that it contributed heavily to Linux and other projects — did not fully resolve the governance question.
By 2023, GitHub reported more than 100 million developers and over 420 million repositories on the platform. No second platform is close. npm and PyPI handle package distribution for their respective language ecosystems, but GitHub is the upstream for most of what they carry. The default has become so thoroughly default that a project without a GitHub presence is now the exception requiring explanation, not the rule.