For the few people following the old RailsBuntu
Note that The book has now changed its name to:
"Full stack for Ruby Framework"
I started to write this book few years ago, and at the time I was mainly concentrating on Ubuntu. But other times I worked over different flavours of Linux. Therefore the content of the book is not any more specific to Ubuntu but to all Linuxes.
It is also hard to find time to focus on writing so the first is still not ready, but moving towards its goal.