VMScluster still blows away anything else. 20 years ago it was doing what you can only now do with vMotion now... And being able to set a working set per job... And a coherent story for cross-language libraries... I could go on. VMS was a technological tour de force that has yet to be rivalled.

What cluster features were in VMScluster that weren't also in TruCluster? To me the interesting part of TruCluster was the shared filesystem and the application failover. That said, I work for a company now that eschews that kind of tight coupling, because it's expensive to scale the hardware.