OS-9 is a family of real-time, process-based, multitasking, multi-user, Unix-like operating systems, developed in the 1980s, originally by Microware Systems Corporation for the Motorola 6809 microprocessor. It was purchased by Radisys Corp in 2001. It is currently owned by Microware LP.The OS-9 family was popular for general-purpose computing and remains in use in commercial embedded systems and amongst hobbyists.