Featherstitch: Killing fsync() softly

This might be a difference in the use of the word "implemented" - I believe (and do correct me if I'm wrong) that soft updates were designed and written once, for FreeBSD, and then the code was inherited to the other BSDs. But I can see this being interpreted as "exists and works in a production operating system" in which case I would have to list all FreeBSD descended operating systems.

Anyway, please do let me know if soft updates were re-implemented independently at any point. The only instance I know of is the Featherstitch-based re-implementation described in this article.