OpenStep Solaris

Not quite! Sun was a participant in creating the OpenStep standard (the NS class prefix stands for ?NeXT/Sun?) and *created their own implementation* of OpenStep for Solaris. (Just as GNUstep is an independent implementation of the OpenStep spec under the FSF umbrella, and OPENSTEP/Mach and OPENSTEP/Enterprise were NeXT?s implementations.) OpenStep Solaris was released, both the user and developer environment, and you should be able to find them today and install them on Solaris 2.5 or later. I think OpenStep will run on everything through Solaris 7 or Solaris 8, but at some point it stopped working because it required Display PostScript in the window server. Indeed, that was post-OpenStep; they weren?t buying companies like Lighthouse to get a suite of applications for OpenStep Solaris, they were buying them to port their stuff to Java (since Java was based rather heavily on Objective-C, and some aspects of the Java frameworks? designs on OpenStep).