Openpixels is a project of mine to create a free and open source artistic framework for game projects in any language or platform. It is going pretty well.
You can just download a zip or tar.gz of the latest version.
You may want fork it or get a git working copy of it to later make your own contributions to the project. In this case:
apt-get install git-core cd ~ git clone git://github.com/silveira/openpixels.git
You will see something like this:
Cloning into openpixels... remote: Counting objects: 129, done. remote: Compressing objects: 100% (126/126), done. remote: Total 129 (delta 17), reused 0 (delta 0) Receiving objects: 100% (129/129), 784.52 KiB, done. Resolving deltas: 100% (17/17), done.
And now you have a repository clone at ~/openpixels and you can start hacking.