Word Cloud
https://github.com/epicdevs/Word-Cloud/
Java code for generating word clouds
The algorithm used in the codes is very sloppy, generating word clouds with random trials.
If you want to know sophisticated algorithms for word clouds, please refer to
http://static.mrfeinberg.com/bv_ch03.pdf
http://mathematica.stackexchange.com/questions/2334/how-to-create-word-clouds/2360#2360