Sleep Is Death is an innovative 2-player storytelling game by Jason Rohrer that encourages users to draw the backgrounds and characters for their stories. Although there are basic pixel painting tools built into the game, InSiDe was developed to allow players to bring more complex or already-existing artwork in, as well as to easily create and manipulate SiD resource packs to share their creations with others.
Mono can run InSiDe on OSX 10.6 and Ubuntu with most features intact. Install it on your OS of choice, then...
Install the WinForms library – open a terminal and enter
sudo apt-get install libmono-winforms*
To launch the application, navigate to where you’ve unpacked InSiDe and use
Run it directly from the terminal, as above. User 'uselessness' in the SiD community also wrote an OSX launcher for InSiDe that I have mirrored for download here.