Your Electronics Open Source

DSPOS, Motorola 56800E DSPs, StarCore, BlackFin DSPs, ARM7/9, features VoIP reference design and Unicoi Fusion Suite.

DSPnano, RoewBots' OS for PIC24, dsPIC30, dsPIC33. A signal processing operating system intended for small signal processors and small DSP networks. Offers an IDE, Compilers, Debuggers, nano-kernel, I/O, and DSP.

EFOS, from Vinjey, an embedded software solution and services company.

DSP/BIOS from TI provides a rich set of deterministic kernel services that enable developers to create sophisticated applications without compromising real-time deadlines. DSP/BIOS is highly scalable with multithreading configurations requiring as few as 1K words. The kernel services may be invoked through either a C function or an assembly language macro interface.

Blackfin Processor OS from ADI site. You can see a lot of well-known RTOSes have already ported to Blackfin DSP/RISC chip.