We at Sine Nomine Associates read the entrails wrong.
We did a port of OpenSolaris to the zSeries architecture (although we required z/VM; much like Linux, there's no point running it otherwise). By "we" I mean mostly Neale Ferguson for the heavy lifting and me for most of the userland apps and toolchain stuff (although I did write most of the disk device driver, which went through z/VM DIAGs rather than talking directly to the hardware, but from the OpenSolaris perspective it was just a device driver).
Both we and IBM thought IBM was going to buy Sun. I'm sure that's why IBM agreed to give us a couple extra DIAGs in z/VM to make the thing run a good deal more efficiently.
And then IBM pushed too hard on price, apparently not knowing Sun was also sitting on an offer from Larry Ellison.
My career would have been very different if that acquisition had happened.
Adam