Jinix is Java based computer operating system that runs on top of the Linux kernel and is based on the architecture of the GNU Hurd. The goal of the project is to provide an operating system largely written in Java that leverages the ubiquity and extensive hardware support provided by the Linux kernel, but replaces much of the non-kernel portions of the OS with Java software. Another goal of the project is to provide a superior runtime environment for Java based application software.
For more information on getting started with Jinix, take a look at the project Wiki. It includes more detail on the Jinix architecture and instructions on installation and configuration.