BitKeeper was first utilized by a Linux project in December of 1999, when it was employed by the Linux PowerPC project. Then in February of 2002, Linux creator Linus Torvalds decided that BitKeeper was "the best tool for the job" and started using it to manage the mainline kernel, an event that received much attention in the free and open source communities [story], and beyond. BitMover, the company behind BitKeeper, was founded by its current CEO, Larry McVoy [interview], who originally conceived of BitKeeper as a tool to keep Linus from getting burnt out by the growing task of managing the Linux Kernel. Since Linus began using the tool three years ago, the pace of Linux kernel development has doubled [story].
There are two definitions for the word "free" that are commonly used to describe software. The first is "Free as in Freedom", and the other is "Free as in Free Beer". BitKeeper was made available freely under the latter definition, allowing free and open source software developers to use the tool without having to pay any money. It was provided under the agreement that anyone actively using the free tool would not develop a competing product at the same time. In other words, the aim was to provide a tool that could be freely used, but not freely cloned. At the same time, a more advanced version of BitKeeper has been sold commercially, and both products remain the intellectual property of BitMover.
A vocal group has long protested Linus' use of BitKeeper, considering Linux the free and open source flagship product. GNU Project founder Richard Stallman [interview] is among the protestors, harshly criticizing Linus' decision to use a non-free (as in freedom) tool [story]. However, most acknowledge that no free tool currently exists that is as powerful as BitKeeper, offering the ability to perform truly distributed development. Attempts to reverse engineer some of BitKeeper's features have lead to repeated cautions by BitMover. Most recently two such reverse engineering attempts have contributed to BitMover's decision to end the development and availability of the free BitKeeper product.