Microware is the corporation that produced the OS-9 operating system.

Microware Systems Corporation existed as a separate entity from 1979 until September 2001, when it was bought by RadiSys Corporation and became a division of that company. Microware initially produced a version of BASIC and a real-time kernel for the Motorola 6800 processor, and was asked by Motorola to develop what turned into BASIC09 for the then-new Motorola 6809 processor. Having written BASIC09, they decided it needed an operating system underlying it, and created the first version of OS-9.

OS-9 went on to versions for the 68000 family of processors and, rewritten mostly in C, to the 80x86, Power PC, ARM, MIPS, and some of the Hitachi SH series of processors. Initially, in the days of the SS-50 and SS-50C bus systems such as SWTPC, Gimix, and Smoke Signal Broadcasting, OS-9 was used more as a general purpose microcomputer operating system, and had a large, active hobbyist user population as well as industrial and embedded system users; this was especially true when OS-9 was available for popular 6809-based computers such as the FM-7, FM-77, and the Tandy Color Computer and its near-clone, the Tano Dragon. However, as time went on, Microware concentrated on industrial customers and neglected the hobbyist base that was porting a great many Unix packages and utilities to OS-9.