A word of warning: if you require fancy graphically oriented development environments, you will be sorely disappointed in the Sway Programming System. Sway is programming at its simplest: a prompt at which you type in expressions which the Sway interpreter evaluates. Of course, you can create Sway programs using your favorite text editor (mine is vim). Sway can be used as a scripting language, as well.
Procedures for downloading and installing Sway can be found at http://sway.cs.ua.edu.
In a terminal window (DOS box on MS Windows), simply type the command:
and press the <Enter> key. You should be rewarded with the Sway prompt.