Microware Systems Corporation existed as a separate entity from 1977 until September 2001, when it was bought by RadiSys Corp., and became a division of that company.

The rights to Microware OS-9 and related software were purchased by a group of distributors on 1 March 2013.

Having written BASIC09, they decided it needed an operating system underlying it, and they created the first version of OS-9.

Initially, in the days of the SS-50 bus 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.

Over time, Microware concentrated on industrial customers and neglected the hobbyist base that was porting a great many Unix packages and utilities to OS-9.