The OpenBSD project produces a free, multi-platform 4.4BSD-based UNIX-like operating system. Its goals emphasize portability, standardization, correctness, proactive security, and integrated cryptography. OpenBSD supports binary emulation of most programs from SVR4 (Solaris), FreeBSD, Linux, BSD/OS, SunOS, and HP-UX.
Mettā is an OS for mobile, multimedia, and social applications. Mettā's purpose is to be easily deployable over a range of mobile and home devices, without tedious setup procedures, while allowing people to communicate easily in a very ambient way and express themselves freely by creating, modifying, and publishing text, audio, and video information in a simple way. Mettā's flexibility comes from transparent resource manipulation and transparently distributing computing tasks between nodes on the network, while maintaining data integrity and privacy.
MutekH is a portable and free operating system for embedded platforms originally developed at the SoC department of the LIP6 Laboratory in Paris. MutekH is a set of libraries built on top of an exo-kernel designed to support heterogeneous multiprocessor platforms. MutekH is fully configurable to match every application's needs. It is used in several research projects and currently supports x86, arm, mips, and powerpc processors.
MBSL (MicroBlaze Simple Linux) is a set of Makefile scripts to create an image of a Linux-based OS for the Xilinx MicroBlaze (FPGA) soft processor. It provides very simple package management that allows you to customize the resulted image. The purpose is to just type 'make build install' and get the configured image.