I'd like an IC that counts down. I tried building one myself, but I'm not sure on the process of setting up a build system for compiling the plugin. There's not ant XML or makefile or anything included that I could see.

Here's the code I wrote (completely untested):
http://davr.org/uploads/MC3101.java

Basically my goal is to be able to time processes which happen in the world, or perhaps have a button you click and then something turns on for a while, or delayed reaction, etc, without having to create a bunch of redstone torch inverters to introduce delay loops.

See the comments at the top of the JAVA file for explanation of how I mean it to work (again...untested)

Added from pull request.