BitKeeper is a distributed version control system created by Larry McVoy’s company BitMover. The project’s own site describes it as built for scale and speed, with safety features for handling large repositories, and now distributes it “as Open Source under the Apache 2.0 License.” Before that release it was a commercial product, offered free to open source projects under a license that barred users from building competing tools.
On those terms the Linux kernel adopted BitKeeper in 2002. It gave kernel developers a genuinely distributed workflow, letting many maintainers keep their own full repositories and exchange changes, an approach that mainstream free tools of the era did not provide.
The arrangement collapsed in 2005. After Andrew Tridgell produced software that interoperated with BitKeeper repositories, BitMover announced it would stop providing the free version to the kernel community. LWN’s report from that April records McVoy framing it as an open source community problem and naming a developer doing interoperability work as the trigger. Linus Torvalds responded by writing git, and Matt Mackall started Mercurial around the same time.
In May 2016, more than a decade after git appeared, BitMover open-sourced BitKeeper under the Apache 2 license. McVoy told LWN the decision came because git and GitHub “has all the market share” and competing with that “just proved to be too hard.”