Agnix is a small, educational operating system kernel for i386, supporting 32-bit protected memory mode, paging, hardware switched tasks, memory tests, PCI bus, devices, PCI IRQ routing, RT timers, network protocols. It is available with all the source code and is fully compatible with the Linux kernel API.
Alpaca is a multitasking operating system for Z-80 based arcade hardware. It has been designed to run on both Pac-Man and Pengo based arcade machines, but can easily be ported to other machines with similar architectures. It supports four concurrently running processes, task switching, simple inter-process messaging, semaphores, and a basic window-based graphical interface.
Buenos is a small SMP operating system skeleton that can be used as a base for operating systems project courses. The system is intended to be used as OS project base code which students can improve. Extensive documentation with suggestions for assignments or exercises is included with the system. It runs in a machine simulator called YAMS, which is its sister project.
DragonFly belongs to the same class of operating systems as other BSD-derived systems and Linux. It is based on the same Unix ideals and APIs and shares ancestor code with other BSD operating systems. DragonFly is differentiated from other operating systems in its class by, among others, the HAMMER file system, Virtual Kernels, swapcache, and the pervasive use of soft token locks. DragonFly provides an opportunity for the BSD base to grow in an entirely different direction from the ones taken in the FreeBSD, NetBSD, and OpenBSD series.
EV-OS is an operating system which runs in real mode on the x86 platform. The system must be booted and run from floppy disk. The user interface is command-line based. Application programs must be prepared for operating system. EV-OS application programs can be developed under the Windows operating system, and a special tool is used to transfer files from Windows to EV-OS. EV-OS is written in assembly and the transfer program is written in C. The downloadable package contains an executable image file, the source code of the operating system, and some installation documentation.
HeavenOS is an original, alternative 32-bit operating system for Intel 80386 compatible processors. It is made with NASM (The Netwide Assembler), and is not intended to compare to modern operating systems, but to try to get the best features and discover better ways to do things. It is intended to be a simple and pratical platform for development, running with a small amount of code.
HelenOS is a microkernel-based multiserver operating system designed from scratch. By decomposing the operating system functionality into tens of isolated but intensively communicating userspace servers, it provides a computing environment that has several virtues such as flexibility, increased robustness, well defined explicit interfaces, and smaller complexity of individual components. HelenOS does not aim to be another clone of Unix or some other legacy system and is not POSIX-compliant (even though it may seem POSIX-similar at times). Instead, the goal has been to design it according to what is the most elegant and right thing to do. What makes HelenOS unique among the other multiserver operating systems is its multiplatform and multiprocessor microkernel. It will run on seven different processor architectures ranging from a 32-bit uniprocessor little-endian ARMv4 to a 64-bit multicore big-endian UltraSPARC T1.