During its annual developer conference, the Cupertino, California-based company said the two app platforms will merge next year, allowing apps built for its iOS mobile operating system to also run on Mac computers.
Much open source software is seemingly on the move, as the also-ran GitLab repository benefits from GitHub's sale to Microsoft.
Microsoft has confirmed plans to acquire GitHub in a stock deal worth $7.5 billion. Open source software is GitHub's sweet spot, and many are concerned with what could happen to the platform under Microsoft's care.
Microsoft expects the deal to close by the end of 2018. The shares were up 0.6 percent to $101.38 at 9:55 a.m. in New York.
GitHub preferred selling the company to going public and chose Microsoft partially because it was impressed by Chief Executive Officer Satya Nadella