In this article I will show you how to install DrRacket, a popular Scheme editor and compiler, on Ubuntu 13.04, Ubuntu 12.10 and Ubuntu 12.04.

The generical steps are: add the PPA, update the system, install DrRacket.
DrRacket is a very popular Development IDE, mostly used for Functional Programming.
How to install DrRacket on Ubuntu 13.04:
Add the PPA:
$ sudo su
# echo "deb http://ppa.launchpad.net/plt/racket/ubuntu raring main" >> /etc/apt/sources.list
# echo "deb-src http://ppa.launchpad.net/plt/racket/ubuntu raring main" >> /etc/apt/sources.list
Update:
# apt-get update
Install DrRacket:
# apt-get install drracket
How to install DrRacket on Ubuntu 12.10:
Add the PPA:
$ sudo su
# echo "deb http://ppa.launchpad.net/plt/racket/ubuntu quantal main" >> /etc/apt/sources.list
# echo "deb-src http://ppa.launchpad.net/plt/racket/ubuntu quantal main" >> /etc/apt/sources.list
Update:
# apt-get update
Install DrRacket:
# apt-get install drracket
How to install DrRacket on Ubuntu 12.04:
Add the PPA:
$ sudo su
# echo "deb http://ppa.launchpad.net/plt/racket/ubuntu precise main" >> /etc/apt/sources.list
# echo "deb-src http://ppa.launchpad.net/plt/racket/ubuntu precise main" >> /etc/apt/sources.list
Update:
# apt-get update
Install DrRacket:
# apt-get install drracket