Wikipedia
Microport (1985–2002) created the first version of AT&T UNIX System V for the IBM 286 and 386 Personal Computers, as well as IBM's PS/2 systems. Together, these IBM families formed the backbone of what is now known as the Intel x86 architecture.
By taking a new (at the time) approach, they were able to dramatically reduce development costs, and consequently, the price charged for UNIX.
At the Free Software Foundation (FSF)'s request, Microport donated a complete 386 development system to the Richard Stallman-led group. This was done for the explicit purpose of enabling the FSF to port its GNU C compiler (gcc) and associated utilities, onto the x86 architecture. GCC was, and still is, one of the largest free software projects available, permitting both the BSD and Linux programmers to develop those operating systems in the 1990s.
Microport also played a key role in Kevin Mitnick's first arrest, after he broke into the internal computer networks of both Microport and The Santa Cruz Operation.