proDMX allows to send and receive DMX messages through the serial port.
Check codeanticode's blog and twitter feed for updates.
For usage feedback, please post to the discourse section in the Processing's website.
For development support (bugs reports, feature requests), use sourcerfoge's trackers and forums.
Unzip and put the extracted proDMX folder into the libraries folder of your processing sketches. Reference and examples are included in the proDMX folder.
Reference. Have a look at the javadoc reference here. a copy of the reference is included in the .zip as well.
Find a list of examples in the current distribution of proDMX, or have a look at them by following the links below.