Constantine Murenin offered a history of the OpenBSD hardware sensors framework during his talk at BSDCan 2008, describing how it was originally based on a port from NetBSD, then evolved and was eventually ported to all the BSDs. He also discussed his own involvement with the framework, having ported it from OpenBSD to FreeBSD as a Summer of Code project, and how his port was merged into DragonFly BSD. At the end of the talk, there were some interesting ecxhanges between Constantine and Poul-Henning Kamp, the latter explaining why he'd had the code backed out of FreeBSD and why he continues to oppose it being merged back in.