Opengl & SDL in Ubuntu

After you've installed Ruby in Ubuntu, you'll want to update Rubygems & install some more software.

First to update Rubygems, type the following in a terminal.

sudo gem update --system

If you get an error such as...

Attempting remote update of rubygems-update
ERROR: While executing gem ... (Gem::GemNotFoundException)
Could not find rubygems-update (> 0) in any repository

Just run the update command again, it should work after a few attempts.

Now type the following in a terminal.

sudo apt-get install ruby1.8-dev

Now type this...

sudo gem install rake

Now enter this...

sudo gem install mkrf

Now this...

sudo apt-get install rake

Also type this...

sudo apt-get install freeglut3-dev

Type this in also...

sudo gem install ruby-opengl

Now install SDL...

 sudo apt-get install libsdl-ruby1.8

Finally install Rubygame...

sudo gem install rubygame