aenix (Adam and Eriks NIX) is a small hobby operating system.
If you are running Ubuntu 10.10 or later, these can all be installed by running
sudo apt-get install build-essential nasm genisoimage bochs bochs-x
cd src make
cd src make run
The book The little book about OS development is based on our experience writing aenix. Everything described in the book is used in aenix.