Linux kernel an SCM system which satisfied Torvalds' technical requirements. BitKeeper was made available to Linus and several others free of charge but was not free software, which was a source of controversy. The system did provide some interoperability with free SCM systems such as CVS and Subversion. In April 2005, efforts to reverse-engineer the BitKeeper system by Andrew Tridgell led BitMover, the company which maintained BitKeeper, to stop supporting the Linux development community. In response, Torvalds and others wrote a new source code control system for the purpose, called Git. The new system was written within weeks, and in two months
Tanenbaum–Torvalds debate titled "Can We Make Operating Systems Reliable and Secure?". While Tanenbaum himself has mentioned that he did not write the article to renew the debate on kernel design, the juxtaposition of the article and an archived copy of the 1992 debate on the technology site Slashdot caused the subject to be rekindled. Torvalds posted a rebuttal of Tanenbaum's arguments via an online discussion forum, and several technology news sites began reporting the issue. This prompted Jonathan Shapiro to respond that most of the field-proven reliable and secure computer systems use a more microkernel-like approach. Tanenbaum–Torvalds debate The Tanenbaum–Torvalds debate was