Using Darkstar 2D in a CAPTCHA system
Darkstar 2D, the system that powers Surface, can also be used in web applications. Here is a simple example in the form of a visual barrier. Darkstar 2D also supports rendering over Java RMI if you need to be able to read Photoshop PSD files on a Mac from a Linux server. The RMI code takes forever to initialize but is quite snappy when operational.
This example is running on a Linux box and uses -Djava.awt.headless=true since it has no GUI system installed.