Comal-Linux is a Linux distribution derived from Slackware Linux. It is packaged as a live CD, and is intended for desktop users who want to use Slackware Linux without first installing it on their computers. Comal-Linux is built from "pure" Slackware Linux, making it as compatible with the original as possible, including application packages. By choosing lightweight desktop and application software, the distribution can be used on older computers. Comal-Linux is an unofficial Muslim edition of Slackware.
GNU Mach is the microkernel upon which a GNU Hurd system is based. It provides an Inter Process Communication (IPC) mechanism which the Hurd uses to define interfaces for implementing in a distributed multi-server fashion the services a traditional operating system kernel provides. Mach is particularly well-suited for SMP and network cluster techniques. Thread support is provided at the kernel level, and the kernel itself takes advantage of that. Network transparency at the IPC level makes resources of the system available across machine boundaries.
Controlix is a control theory based operating system. It abstracts the complete abstraction hierarchy of computer systems principles, from basic signal-on-wire all the way up to abstract libraries and interface linkage. It is written in the VHDL language and is designed to be modular, synchronous, and retargetable.
μnix is an open source DIY hardware and software project that endeavors to create a complete, usable, computer workstation using only discrete components, IC chips, and 8-bit microcontrollers. The electronic design, including the schematics and PCB layout, is open and usable by anyone. In addition, the necessary firmware for all of the ancillary microcontrollers is provided, including the advanced firmware acting as the Operating System on the main CPU units. The goal is not to try to create a competing product with any of the x86 computers out there, but instead to learn and teach the very low-level information and skills needed to create a complete workstation from scratch, starting from the circuit boards and ending with the multitasking OS. The project is open to anyone that wants to contribute or even just be involved in some way with a project of this scope and innovation.
BugOS is a microkernel operating system. It has a kernel, device drivers, a file system, and an Internet module. The main concepts are that every process has its own computer with its own console, security, and modularization. If a process wants to read the file, it asks the kernel. The kernel forwards the request to the filesystem driver, which reads and writes through the partition handler, which operates over the idehdd driver. The kernel is around 20 KB. Processes are fully separated from hardware.
Cross Linux From Scratch (CLFS) is a project that provides you with step-by-step instructions for building your own customized Linux system entirely from source. This is a multi-architecture version of Linux From Scratch that is cross-compiled. It currently supports Alpha, MIPS, PowerPC, Sparc, x86, and x86_64.