NixOS is an open source Linux distribution based on a lazy functional programming language called Nix.
NixOS works well, as primary operating system, on my laptops. This distribution has a lot of features which are awesome. When we compare the features of this distribution to others, we are just amazed by the evolution.
Here is an extremelly short list of features:
As a user, you don't want to hack into the code to extend the system to handle your specific needs. This is the challenging tasks I took. This had implied to rewrite the core structure of NixOS to have modular configuration files.
Now we are able to express services, hardware and computer configuration in a modular fashion. Thus, you no longer need to look at forum to find out how to install and configure software. What you need is to look at the NixOS manual to set what services you want.
The work done on this distribution has been documented inside a research paper which is published in the Journal of Functional Programming. You may also find a video (NixOS' configuration system) in which I present this work at the FOSDEM 2010
In addition, I wrote an article about of the history of NixOS which is available in the magazine Programmez! 128 at the page 42.