By default, Ruby is installed on the Eee PC. However, it is lacking both the rdoc and irb packages needed to follow many books (eg. Beginning Ruby) and other learning material provided by academic institutions. This How To describes how to install rdoc and irb, and ensure that your Ruby is compatible with them, without making any other lasting changes to your system.
Ctrl Alt Tsudo nano /etc/apt/sources.listdeb http://ftp.uk.debian.org/debian stable main contrib non-freeCtrl X, press Y, press Return.sudo apt-get updatesudo apt-get install ruby irb rdocY, press Return.sudo nano /etc/apt/sources.listCtrl X, press Y, press Return.sudo apt-get updateexit