Microport

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.