Shadok is a tool written by Stéphane Bortzmeyer to verify and create graphs for state machines written in a very simple language named Cosmogol. Everything is explained at the following URL:
http://www.cosmogol.fr/shadok.html
The language was proposed some time ago to the IETF as a way to describe a state machine inside a text document like an RFC. I still think that this is a great idea and in the hope that more people use it I packaged it for Debian and Ubuntu and uploaded it on a public Debian repository.
To access this repository, add the following lines in your /etc/apt/sources.list file:
deb http://debian.implementers.org/ testing/$(ARCH)/
deb http://debian.implementers.org/ testing/all/
deb-src http://debian.implementers.org/ testing/source/
You will also need to install a GPG key to verify the repository:
$ wget http://debian.implementers.org/keys/key.asc
$ sudo apt-key add key.asc
The fingerprint of the key is as follow:
CDB3 BC52 DFDC 8A58 35F1 714D 0309 943D 9AD0 8F3F
You can then run the following commands to install the shadok package:
$ sudo apt-get update
$ sudo install shadok
The repository contains only the binary packages for the i386 and amd64 architectures. You can download the source and recompile it for other architectures with the following commands:
$ sudo apt-get build-dep shadok
$ apt-get source shadok
$ cd shadok-0.0.0
$ dpkg-buildpackage -D -b -us -uc
Enjoy!