GitHub is a web platform for hosting git repositories. It went public on April 10, 2008, with a short announcement on its own blog titled “We Launched,” which read in part: “GitHub is officially live. Thanks for the awesome beta everyone.” It was built by a small group of Ruby developers who wanted a friendlier, more social home for code stored in git.
GitHub’s central contribution was making collaboration social. Around git’s underlying mechanics it added a web interface, public profiles, and the pull request: a way to propose changes to someone else’s project, discuss them in line with the code, and merge them with a click. That workflow lowered the barrier to contributing to open-source software, since anyone could copy a project, make changes, and offer them back without prior coordination.
The platform grew into the default place where open-source projects live and where many developers present their work publicly. Hosting code, tracking issues, and reviewing changes in one place made it a hub not just for individual projects but for the broader culture of open collaboration that git enabled.
In June 2018 Microsoft announced an agreement to acquire GitHub. The company’s own announcement stated that “Microsoft Corp. on Monday announced it has reached an agreement to acquire GitHub for $7.5 billion in Microsoft stock,” with GitHub continuing to operate as a developer-focused platform. The acquisition placed one of the most important pieces of open-source infrastructure under a company that had once been the open-source movement’s chief adversary.