Which company owns the GitHub software-development platform?

Microsoft owns the GitHub software-development platform.

Microsoft announced its agreement to acquire GitHub in June 2018 and completed the acquisition later that year. GitHub is a web-based platform for hosting and collaborating on software projects that use Git, a distributed version-control system. Developers use repositories, branches, pull requests, and issue tracking to coordinate changes.

GitHub was founded in 2008 by Tom Preston-Werner, Chris Wanstrath, P. J. Hyett, and Scott Chacon. Before Microsoft acquired it, GitHub had become one of the most widely used collaboration services for open-source and private software development.

GitHub continued operating as a separate platform after the acquisition. Microsoft also uses GitHub as part of its developer ecosystem, alongside products such as Visual Studio and Azure. A common mistake is to treat GitHub as Git itself: Git is the version-control software, while GitHub is an online service built around Git repositories and collaboration tools.