The GNU Hurd project is a set of servers running on top of the GNU Mach microkernel. Together they build the base for the GNU operating system.
Currently, Debian is only available for Linux, but with Debian GNU/Hurd we have started to offer GNU/Hurd as a development, server and desktop platform, too. However, Debian GNU/Hurd is not officially released yet, and won’t be for some time.
The Hurd is under active development, but does not provide the performance and stability you would expect from a production system. Also, only about every second Debian package has been ported to the GNU/Hurd. There is a lot of work to do before we can make a release.
Until then, you can participate in the development if you want. Depending on your experience and time commitment, you can help us in many different ways. For example, we need experienced C hackers to develop and implement new features and to fix bugs and debug the system.
If you are not very experienced in C programming, you can still help: Either by testing the existing systems and reporting bugs, or by trying to compile some unported software you have experience with. Also writing documentation is important, or maintaining the web pages.