Open Source RTOS simulator based on event-driven simulation methods with concurrent target debugging abilities, mimics OS behavior, to implement and test embedded software on workstations. Descriptions, downloads, documents. [Savannah, Open Source, GPL]

Microkernel RTOSs and set of integrated tools to develop embedded realtime applications, made to support all architectures used in power train controllers in automotive industry. Kernels have 2 main layers: Kernel Layer, Hardware Abstraction Layer, HAL. [Open Source, GPL]

Benefits of open source compared to other RTOS licensing models.

Portable, mini realtime scheduler (RTOS kernel); how to make full embedded solutions on Windows host with quality open source tools, low cost hardware; supports ARM7, PIC18, 8051, Atmel(Mega)AVR, RDC8822 (AMD AM186 clone), PC with DOS. [Open Source, GPL]

Home page real-time operating system (Katix RTOS) and Katix Embedded Linux (Black Cat Linux). [Open source]

Free, tiny.

Compares 2 open source OSs for embedded uses: RTLinux, eCOS by Cygnus.

Graphical realtime OS written in all 32-bit assembly, for x86 i386+, fits on one floppy, protected memory, 44 kHz sound soon, GUI, DOS loader download; advancing well. [Open Source, GPL]

A multitasking embedded operating system with a proven track record, expressly designed for embedded devices with limited resources.

Makes 2 very small, open source realtime OSs for embedded systems, written in C: proc Real-Time Kernel, preemptive, mature; nesos Finite State Machine Operating System (FSMOS), modular, use concurrent programming methods in little time and space. Also: nemon Boot and Debug Monitor; Embedded Web Servers.

Makes RadiOS, Radiant Operating System; realtime, multitasking, multiuser, for i386+, written in all assembly in NASM. Goal: create OS that combines all advantages of OS/2 and Unix; ftp downloads. [Public Domain]

One-user, general purpose OS built on a protected memory, POSIX threads RT kernel; full kernel, device drivers, file systems, and network protocols runs in about 200 K RAM; now runs on x86 CPUs but designed for easy portability. [GPL]

Realtime microkernel: preemptive, fully re-entrant, multithreaded, SMP, continuations, full locking primitives; shares many ideas with Mach, developed by CMU in late 1980's, early 1990's, stopped in 1994. [GPL]

Makes RTMX O/S: IEEE POSIX realtime extensions to OpenBSD, with vendor specific ports for embedded, dedicated systems, application specific Internet/intranet servers. Many fine features. North Carolina, USA.

Ideal for tiny, low power devices; coded in C; permits embedding OS in any application for multi-threading. This works if host is Linux, Windows 95/98/Me/NT/2000, or an embedded project with no OS. If applications run in Linux or Windows, RTX provides no hard-real time as direct interrupt mapping to threads is prevented.

Dynamic configurable kernel architecture to support hard/soft/non realtime use with interchangeable scheduling algorithms: fully modular in scheduling policies, aperiodic servers, concurrency control protocols; all not modular in most traditional OSs. Derived from HARTIK: HArd Real TIme Kernel. [GPL]