CP/M 86 3.x

CP/M-86 is a port of Digital Research's CP/M operating system to the Intel 8088/8086. The earlier CP/M-80 was extremely popular on 8080/Z80 microcomputers.

It was anticipated that CP/M-86 would be the de-facto operating system on IBM's 8088 based IBM Personal Computer. However after a failure between Digital Research and IBM to coordinate a license for the IBM Personal Computer's August 1981 release, IBM instead partnered with Microsoft to release PC-DOS. CP/M-86 for the IBM PC was released on April 1982, but by that time DOS already had a foothold.

CP/M-86 was ported to a number of non IBM compatible platforms that also used the x86 CPU. It later evolved in to DOS Plus and DR-DOS and branched in to Concurrent CP/M-86

CP/M is currently open sourced under the BSD license.