The clouds give greater prominence to words that appear more frequently in the source text. You can tweak your clouds with different fonts, layouts, and color schemes. The images you create with Wordle are yours to use however you like. You can print them out, or save them to the Wordle gallery to share with your friends.
Wordle is implemented as a Java applet. It’s popularity can be gauged by the fact that its users have over 2,000,000 word clouds to Wordle's public gallery.
The tool’s creator Jonathan Feinberg built it while he was at IBM Research and he now works for Google. He has authored a chapter for the book Beautiful Visualization, where he explains how Wordle came to be & how it works.
Below is the “tag cloud” of labels/tags (click to enlarge) that I’ve used on my blog, created with Wordle’s “advanced” interface.
