When NeXT, Inc. sold its business to Apple, the NeXT/OpenSTEP operating systems went unsupported. New hardware emerged in the x86 market, and NeXT was not able to boot successfully anymore (among others, problems with the CD-rom drivers, while the last CPU it supported was the Pentium Pro). However, a few NeXT “die hards” have managed to boot OpenSTEP under VMWare, the x86 runtime application. You can find instructions here and here on how to run OpenSTEP under Linux and Windows’ VMWare respectively (screenshots included). Moreover, Atomic Object, Inc. released a SVGA OpenSTEP display driver for VMWare (although the graphics VMWare specs are not publicly available), so now the OS is almost fully supported by VMWare, even so unofficially. On a related note, the GnuSTEP project moves in a faster pace lately, trying to implement the OpenSTEP and MacOSX’s Cocoa APIs.