Realtime preemptive kernel coded fully in C, so is highly portable to different hardware platforms and easily embeddable; Descriptions, full source code, examples, C Style Guide and programming Guidelines. [Free]
Makes multitasking RTOS products: CMX-RTX (full RTOS), CMX-TINY+ (small RTOS), CMX-TCP/IP, CMXBug, CMXTracker. These support most 8/16/32/64-bit embedded controllers, processors, DSPs, over 30 compiler vendors.
Develops and distributes the OSE family of real-time operating systems and embedded development tools for high reliability telecom/datacom, medical, automotive and safety critical applications.
Details the specs for the Fusion RTOS from Unicoi Systems, an embedded software provider which delivers its RTOS to customers, free of charge.
JMI Software Systems, Inc.
Makes C Executive and PSX multitasking, ROMable kernels for embedded systems. C Ex runs on 8/16/32 bit CISC CPUs, many RISC CPUs, DSPs, over 20 so far: fast context switch, compact. Options: DOS file system, TCP/IP, SNMP. PSX is medium-size kernel, between small basic kernels and full Unix; optional subset of POSIX.1 system calls.
Kadak Products Ltd.
Makes AMX RTOS, KwikNet TCP/IP stack and Web server, KwikLook fault finder, KwikPeg GUI with graphics library. A high quality realtime software foundation for embedded products.
Micro Digital, Inc.
Makes SMX: no-royalty, modular, preemptive multitasking, small fast, many featured RTOS for embedded systems. Portable to all 32-bit processors, now on ARM, ColdFire, PowerPC, SH3/4, x86. Unlike generic C kernels, it exploits strengths of x86 to make it easier to program.
On Time Informatik GmbH
Makes RTOS-32, and realtime multitasking development tools, for x86-based embedded systems; no royalty, full source code available on all products. Supports Borland, Microsoft, Watcom C/C++ compilers; DOS, Win32 compatible API gives easy ports of extant programs.
Plan 9 from Bell Labs Real Time Capabilities
A collection of papers about the real time capabilities of the Plan 9 kernel.
Makes Salvo RTOS, designed expressly for very low cost embedded systems with highly limited ROM and RAM (normal uses: 1-2K ROM, 50-100 bytes RAM) and/or no software stack. Priority-based, cooperative multitasking, event services, real-time delays.
QP state machine frameworks
Open source, state machine frameworks for embedded systems by Quantum Leaps.
Quadros Systems, Inc.
Makes RTXC 3.2 and RTXC Quadros, for convergent processing in embedded uses. Seamless use with microprocessors, DSPs. Configurations: single stack, dual stack, multi stack; multicore, multiprocessing.
Realtime Operating System
Growing article, with links to many related topics. Wikipedia.
Assembly coded high performance kernels, internet protocols (TCP/IP), filesystem, support for distributed systems, DRUID system level debugger. Supports most 32-bit processors; COMPACT is for 8/16-bit controllers. By Litronic AG.
SW Datentechnik GmbH
Realtime software, hardware, services: QNX, SQL, multiplatform RAD, portable UNIX-Windows, networking, RAID, multiport.
Segger Microcontroller Systeme GmbH
Makes, sells, supports embOS RTOS for embedded uses, multitasking, minimum cost, no royalty, fully interruptible, efficient for time critical uses, RAM and ROM needs so small it fits 1-chip uses, leaving more room for user programs.
Specializes in real-time virtual machine technology that combines the Windows OS and a hard real-time OS on a single x86 PC compatible computer.
For Z80 and Z180 compatible processors; full-featured, tiny, size ranges from 1k to 2.5k, set by features used; written in pure Assembly, making it maximally small, fast; no royalty; low cost licenses for binary and full source code. By Softools, Inc.
Wind River Systems, Inc.
Makes pSOSystem, OSEKWorks, Virtuoso, VxWorks RTOSs (and BSD/OS). Providing full embedded system software and design automation solutions: software, hardware, custom design, and support.
Realtime OS and development system for programs for industrial automation, telecontrol, machine automation. It is C-Scada: does all functions of SCADA, plus control (more so with neXor I/O hardware); by XPLAB. English, Italian.