FreeNOS is an experimental microkernel operating system for learning purposes, licensed under the GPLv3.
Version 0.0.3 includes a new filesystem written from scratch: LinnFS. It is roughly based on the Extended FileSystem. It is now used as the root filesystem on the LiveCD instead of Ext2.
Additionally, the notion of current directory has been implemented. Finally, this release has also been tested on the latest Nexenta distribution.
You can download FreeNOS from one of these mirrors.