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Bitkeeper is a software tool for revision control (configuration management, SCM etc) of computer source code. A sophisticated distributed system, Bitkeeper competes largely against other professional systems such as Rational ClearCase and Perforce. Bitkeeper is produced by BitMover Inc., a privately held company based in San Francisco, California.

Bitkeeper is a closed-source product, and is normally sold or leased (as part of a support-package) to medium or large corporations. The precise cost varies with individual customer, but the per-developer cost is estimated to be over two thousand dollars.

BitMover also allows access to the system for certain open source or free software projects, the most famous (and controversial) of which is the source code of the Linux kernel. The license for the "community" version of Bitkeeper allows for developers to use the tool at no cost for open source or free software projects, provided those developers do not participate in the development of a competing tool (such as CVS, Subversion or ClearCase). This restriction applies whether the competing tool is open/free or proprietary. This version of Bitkeeper also requires that certain meta-information about changes be stored on computer servers operated by Bitmover, an addition which means that it is impossible for users of the community version to run projects of which Bitmover is unaware.

The choice of Bitkeeper for Linux kernel development was a controversial one. Some advocates, most notably GNU founder Richard Stallman, expressed concern about proprietary tools being used on a free project. While project leader Linus Torvalds and other core developers adopted Bitkeeper, several key developers (including Linux veteran Alan Cox) refused to do so, citing the Bitmover licence, and voicing concern that the project was ceeding some control to a commercial developer. To mitigate these concerns, Bitmover added gateways which allowed limited interoperation between the Linux Bitkeeper servers (maintained by Bitmover) and developers using CVS and Subversion. Even after this addition, flamewars occasionally break out on the Linux Kernel Mailing List, often involving key kernel developers and Bitmover CEO Larry McVoy.

In November 2003, a cracker compromised the CVS interface and attempted to introduce a security defect that would allow the easy operation of trojan horse programs on the resulting kernel. The defect, which masqueraded as a legitimate change by networking architect David S. Miller, was detected and removed within 24 hours of its introduction.