Successors
In spite of Tandy's apparent lack of concern for the CoCo market, there were rumors of the existence of a prototype CoCo 4 at Tandy's Fort Worth headquarters. Several first hand accounts of the prototype came from people like Mark Siegel of Tandy and Ken Kaplan of Microware, yet there exists no known physical evidence of such a machine.
A few independent companies attempted to carry the CoCo torch, but the lack of decent backwards compatibility with the CoCo 3 failed to entice much of the CoCo community over to these new independent platforms. Many of these independent platforms did run OS9/68k, which was very similar to OS-9. However the bulk of the CoCo community moved on to more mainstream platforms. Some CoCo users swore their loyalty to Motorola and moved on to the Amiga, Atari ST, or even the Macintosh, all of which were based on the Motorola 68000 processor. Others jumped to the IBM PC-compatible.
Read more about this topic: TRS-80 Color Computer