Can I Use It?
At the moment, HURD boots, and can run GNOME (and nine CDs of other Debian packages). A few things are still missing, such as entropy collection, which is required for secure random-number generation (and most cryptographic algorithms). The project has been making slow progress for 20 years, and is likely to continue. It’s not the most full-featured—or even stable—kernel, but as a research platform it’s very interesting.
Transitioning to a more modern microkernel at the core will make the system considerably faster, so either L4/HURD or Coyotos/HURD is likely to be a very interesting platform for multicore systems before long.
Even in its current state, HURD exists to prove a point: It’s possible to have a complete and usable system running nothing other than GNU code.