have helped Linux by adding JFS. Looking at the history of JFS on Linux is therefore interesting.
First read Steve Best of IBM announces JFS 1.0.13. Read the post, and you'll notice 5 contributions by a "Christoph Hellwig".
So who is this Christoph Hellwig? He appears to have been a Caldera (former name of The SCO Group) employee posting from a @caldera.de address.
Did he and SCO/Caldera know what IBM were doing with JFS? Well I can't say for sure... but he does appear on the kernel mailing list fairly frequently. It also appears this gentleman might have been working on Linux JFS while at Caldera/SCO in March 2002.
Also on the mailing list, you'll also find more recent posts by presumably the same Christoph Hellwig, who now says he is a former employee of SCO/Caldera."