Enigmatic is a project mainly written in JavaScript, it's free.
An Eniugma Machine for Facebook status posts
Enigmatic is a facebook wrapper for Graham Bradley's JavaScript Enigma Machine simulator.
It lets Facebooker's post encrypted text to their walls and visit the app to get decrypts.
There are functional rotor, ring and patchboard settings so that users can make their messages undecipherable (well, kinda :-) unless they share their settings with others.
The app is plain HTML and javascript.