Hacking the parser

First of all, make sure you've read omath using Eclipse, and checked out the parser project from SVN.

Install javacc
You'll need at least version 4.0beta1. (At this point, this is the bleeding edge release; sorry, but we need it for java 5.0 support.) Download either the .tar.gz or .zip, and unzip it wherever you like.

You'll then need to tell our ant build script where to find javacc. Copy (or rename) local.properties.template to local.properties, and change the javac.home property to point to wherever you put javacc (just the main javacc directory, not its bin directory...)

Install PyDev (optional)
You'll want PyDev (the python plugin for eclipse) to use any of the Python scripts needed for building omath. Installing PyDev is just like adding SVN support to eclipse; the update manager URL is http://pydev.sf.net/updates/

Now you'll need to point PyDev to your Python install (and install Python, if necessary!) Go to Preferences, Pydev, Interpreter - Python, and click 'New' next to the 'Interpreters' box, and select your python executable. Everything else should just work...

A python shell within Eclipse (optional)
If you're a python hacker, you'll want this;

Go to Run|External Tools|External Tools... Go to 'Program' in the list on the left, click new below. Enter the name 'Python shell', enter the location of your python executable, and add argument -i. Click run!