On Sun, Feb 3, 2019 at 2:59 PM Cág &lt;ca6c(a)bitmessage.ch&gt; wrote: Be careful. The history of proprietary commercial UNIX implementations is that they were developed by HW manufacturers that had proprietary ISAs. So that fact that UX was Itanium and AIX was Power (or Tru64 in its day was Alpha) should not be surprising. It was the way the market developed. Each vendor sold a unique ecosystem and tried very hard to keep you in it. Portability was designed as an >>import<< idea, and they tried to keep you from exporting by getting you to use 'value add.' I remember during the reign of terror that Solaris created. Take as an example, the standard portable threading library was pThreads. But Solaris threads were faster and Sun did everything it could get the ISV's write using Solaris Threads. Guess what -- they did. So at DEC we found ourselves implementing a Solaris Threads package for Tru64, so the ISVs could run their code (I don't know if IBM or HP did it too, because at the time, our competition was Sun). BTW: this attitude was nothing new. I've said it before, the greatest piece of marketing DEC ever did was convince the world that VMS Fortran was Fortran-77. It was not close. And when you walked into most people writing real production code (in Fortran of course), you discovered they had used all of the VMS Fortran extensions. When the UNIX folks arrived on the scene the f77 in Seventh Edition was not good enough. You saw first Masscomp in '85, then a year later Apollo and 2 years after that, Sun develop really, really good Fortran's -- all that were VMS Fortran compatible. nobody cares about commercial Unix systems anymore. This is a bit of blind and sweeping statement which again, I would take some care. There are very large commercial sites that continue to run proprietary UNIX on those same proprietary ISAs, often with ISV and in-home developed applications that are quite valuable. For instance, a lot of the financial and insurance industries live here. The question comes to how to value and count it. Just because the hackers don't work there, does not mean there are not a lots firms doing it. Those sites are extremely large and represent a lot of money. The number of them is unlikely to be growing last time I looked at the numbers. In fact, in some cases, they >>are<< being displaced by Intel*64 systems running a flavor of Linux. The key driver for this was the moving the commercial applications such as Oracle and SAP to Linux and in particular, Linux running on VMs. But a huge issue was code reuse. To reuse, Henry's great line about BSD, Linux is just like Unix; only different. Simply has the cost of maintaining your own ISA and complete SW ecosystem for it continues to rise and in fact is getting more and more expensive as the market shrinks. At this point, the only ones left are HP, IBM and the shadow of Sunoracle. They are servicing a market that is fixed. > As far as commercial systems go, even CentOS has a far larger market > share on the supercomputer territory than RHEL does, according to > TOP500. Again be careful. In fact this my world that I have lived for about 40+ years. The Top100 system folks really do not want any stinking OS between their application and the hardware. They never have. Don't kid yourself. This is why systems like mOS (Rolf Riesen's MultiOS slides <https://wrome.github.io/slides/rome16_riesen.pdf> and github sources <https://github.com/intel/mOS/wiki>) are being developed. Simply put, the HPC folks have always wanted the OS out the way. Unix was a convenience for them and Linux just replaced UNIX. The RHEL licensing scheme is per CPU and on a Beowulf style cluster, it does not make a lot of sense. I know a lot of the Linux community likes to crow about the supers using Linux. They really don't Its what runs on the login node and the job scheduler. It could be anything as long as its cheap, fast and the physicists can hack on it. This is a behavior that goes back the Manhatten Project and its unchanged. The 'capability' systems are a high-end world that is tuned for a very specific job. You can learn a lot in that area, but because about making generalizations. As I like to say -- Fortran still pays my salary. These folks codes are unchanged since my father's time as a 'computer' at Rocket Dyne in the 1950s. What has changed is the size of the datasets. But open up those codes and you'll discover the same math. They tend to be equation solvers. We just have a lot more variables. Clem