Ananas (pronounced as pineapple) is my operating system. It consists of a kernel, a loader, assorted builds scripts and a standard C library (which is based on the Public Domain C Library, PDCLib). Ananas has a clear goal: technology-wise to be the easiest-to-understand operating system in existance, and license-wise to be the most free operating system imaginable.
More information is available at my website, with some screenshots and whatnot.
In order to try Ananas or get hacking on it, you will need a Linux environment (I use Debian) with appropriate development tools (sudo apt-get install build-essential is a good start), Git, and a lot of spare time. Details instructions are in the doc/ folder, with getting-started.rxt being a good start.