• HP NonStop
  • HP-UX
  • HP TRU64

I never knew there was an Operating system by HP. And Wikipedia says the versions are being updated still. Who uses them?

For all these, apart from what their websites say, where are these used? by who?


Back before Linux dominated the low-end Unix market, there were several computer hardware companies with their own versions of Unix. Generally, these were mostly the same from the user point of view, but different enough to be annoying. In the 80s they were common on the desktop in universities, government labs, and some businesses. In addition to HP, Sun had Sun OS (before Solaris), SGI had Irix, and even Microsoft had Xenix. These generally ran on fairly powerful and expensive hardware compared to the PCs of the time.

This all came crashing down with the introduction of Linux on commodidy hardware that could do everything the commercial Unix systems could do, for a whole lot less money.

Currently, the only places that these are still being used are applications where its cheaper to pay for continued support rather than port to a new system. This includes high security installations that would have to be completely recertified if the OS changed.


It is worth noting a bit of history here. HP merged with Compaq who in turn had taken over Digital and Tandem.


These brands are typically associated with mainframes or very high end servers (>$100,000 each) - the kind of thing that fills an entire rack. Occasionally you'll find a lone (or paired, for redundancy) HP-UX server running things at a company, but more often these are part of very large data centers/server farms.

  • That's not entirely true. HP-UX is also used on workstations and application servers, which aren't all that big or expensive.
    – garyjohn
    Jul 29 '10 at 16:25
  • Have to agree, hard to call them mainframes. We ran HP-UX on hundreds of firewall boxes that were the same size as your average home PC. Cost for the firewall package deal was in the $10k to $30k region but that was a while back.
    – hotei
    Jul 31 '10 at 20:46

Typical industries that use these include banks, airports, governments, etc.


HP-UX (HP Unix) was used extensively by US Dept of Defense in the 1990's. Several very large contracts from the Air Force to HP specified this OS for the matching HP hardware. It was excellent hardware but a tad pricey. You could even get an Ada compiler for it. :-) No idea if they're still in use ...

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