Wordler is a project mainly written in Ruby, it's free.
Simpe sinatra app that outputs wordle-like word clouds.
...that is just a proof of concept sinatra app to serve wordle-like word clouds.
The algorithm is heavily inspired by the ImageCloud plugin for Wordpress (http://wordpress.org/extend/plugins/imagecloud/).
Image generation relies on rmagick.
Wordlr needs the following gems:
...and of course sinatra
ruby wordcloud.rb...and connect to localhost:4567