Since starting to work recently with ECJ, I've posted several messages about my experiences on my blog, Invisibe Hand. It is available at dvunkannon.blogspot.com. My most recent post shows how I've built on the charting support in ECJ to create charts with multiple data sets per chart that report different statistics about a subpopulation. Please visit and leave some comments! Sean - since the work I am blogging about combines several incremental changes to ECJ in the areas of a new BitVector problem, reading custom parameters, and collecting and charting custom statistics, I was wondering if you would like me to write it up in the form of a tutorial? It's about the same difficulty as Tutorial 2, just in a slightly different direction. Cheers, David vun Kannon