Chimera
Multitasking, multiprocessor OS with features of commercial realtime OSs; as fast as VxWorks, OS-9, VRTX, LynxOS; 10 times faster in some cases: interprocessor communication. VMEbus-based, supports C/C++, goal: support developing dynamically reconfigurable software for robotic and automation systems.

Arx
Full, stand-alone RTOS developed by Real-Time OSs Lab., Seoul National University: fully preemptive realtime kernel, POSIX thread library, multithread-safe standard I/O libraries, TCP/IP suite, VFAT file system, X11 R6 window system, user-level IO.

MaRTE OS
Realtime kernel for embedded uses, follows Minimal Real-Time POSIX.13 subset. Most code is Ada, but some C, assembly. Hardware access via Abstract Hardware Interface (HAL). Runs in cross development environment: PC Linux Host, bare 386 PC Target, Ethernet LAN link. [Open Source, GPL]

MaRTE OS: An Ada Kernel for Real-Time Embedded Applications
Minimal Real-Time Operating System for Embedded Applications follows Minimal Real Time POSIX. subset, has Ada and C POSIX interfaces, allows cross development of Ada, C, or mixed realtime applications with globally consistent scheduling of Ada tasks, C threads. [ResearchIndex] You Would also find info related to Mario Aldea Rivas http ctrpc unican es publications mgh pdf MaRTE OS: An Ada Kernel for Real-Time Embedded Applications3 and Gonzlez Proceedings of the International Conference Reliable Software Technologies Europe and much more.

Mälardalen Real-Time Research Center
At the IDt (CS) Department, Mälardalen University, Sweden. Fine lists of projects, publications, and other documents. Home of Asterix Project: the real-time kernel for the final frontier.

Ptolemy Project
Studies modeling, simulation, and design of concurrent, real-time, embedded systems. Focus: assembly of concurrent components. Key underlying principle: use of well-defined computation models that govern interaction between components.

Real-Time Mach
By Real-Time and Multimedia Laboratory, Department of Computer Science, Carnegie Mellon University. RT-Mach is a resource kernel, a kernel provides resource-centric services, which can then be used to satisfy end-to-end QoS needs.

Real-Time Mach NTT Release
Another version of Real-Time Mach, by NTT Laboratories. Contains RT-Mach kernel, FreeBSD 2.2.8 server, real-time shell, RT-Java, Hurd loader. Site has fine 'Getting Started' section: readme, release notes, installation, hardware, compatibility, troubles Q&A, contacts. You Would also find info related to Real-Time Mach, RT-Mach, operating systems and much more.

ReTiS Lab
Real-Time Systems Lab, St. Anna's School of Advanced Studies, Pisa, Italy; researches innovative algorithms, methods, tools to deal with time-dependent applications. Projects: E.R.I.K.A., HARTIK HArd Real TIme Kernel, S.Ha.R.K.

RTG: Real Time Systems Group
University of Pennsylvania, Philadelphia. Goal: develop methods, tools, systems to facilitate designing and implementing reliable distributed RT systems. Current projects: developing specification and analysis methods for RT systems, probabilistic modeling and analysis, schedulability analysis, run-time monitoring/checking, RT wireless communication and hybrid systems.

RTOS-UH
Hard RTOS, by University of Hannover: mature (usable in real-world systems), compact, scalable from small embedded uses to big development workstations; Motorola-based (MC, MP); uses ISO 9001-2 (software development) as internal guideline, mostly programmed via RT high-level language PEARL90, DIN 66253-2. You Would also find info related to real-time programming, PEARL, RTOS-UH, real-time operating system, embedded systems and much more.

Spring Project
Realtime microkernel and integrated environment, designed and implemented to support/provide predictability, guarantees (on-line dynamic, atomic), end-to-end scheduling, resource reservations; supports call/task admission model; and multiprocessors.

The Spring Operating System
Term paper describing development of this research realtime OS. Good discussion of needed trade-offs, compromises.

XOberon
Hard realtime OS for mechatronics, newest version for PowerPC; loosely based on Oberon OS, coded in Oberon-2. Goal: create framework for non-computer-scientists needing rapid application development (RAD) tool to program embedded systems. You Would also find info related to real-time, oberon, XOberon, PowerPC, time-critical, hard real-time and much more.