Radius Inc. was an American computer hardware firm founded in May 1986 by Burrell Smith, Mike Boich, Matt Carter, Alain Rossmann and joined by other members of the original Macintosh team like Andy Hertzfeld.

Using an ARM processor,[6] this being specifically the VL86C010 device also known as the ARM2 and used in the Acorn Archimedes series of computers,[7] QuickColor offered a claimed 600 percent speed increase in screen drawing operations, although observed performance gains were more modest.

[8] Such reimplemented routines were claimed to run 50% faster on the QuickColor board whose ARM processor ran "a multi-tasking RISC operating system".

[9] QuickCAD was described as "a superset of Radius's QuickColor", offering display list processing in a fashion similar to that of existing coprocessors - already available for IBM PC-compatible systems - such as the TMS34010.

It faced multiple shareholder lawsuits, accusing senior managers of extensive insider trading weeks before announcing the company's first unprofitable quarter; several failed R&D projects; a black eye from its bug-ridden Radius Rocket product; and a lack of market focus.

The SuperMac acquisition netted Radius the Cinepak video compression codec, which was still supported by most encoders and almost all media players by the early 2000s.

[14] In the same year, Radius acquired Reply Corporation, a San Jose–based maker of aftermarket motherboards and x86 compatibility cards for Macintosh computers.