BitKeeper (and the birth of Git)
loreprogrammingops culture
The proprietary distributed version-control system the Linux kernel used from 2002, offered free to the project - and whose withdrawal in 2005, after a dispute over reverse-engineering its protocol, left the kernel abruptly without version control.
Torvalds wrote Git in a matter of weeks to fill the gap, targeting exactly what the kernel needed: speed on a huge tree, distributed operation, and cryptographic integrity of history. The episode is the field's neatest demonstration that infrastructure gets built when someone capable is blocked - and a caution about depending on a tool you cannot fork, however generous the terms look while the relationship is good.
Also known as: bk, kernel version control 2002, larry mcvoy