Youtube video of Another Java open source stock exchange simulator for HFT backtesting with market maker and detail order book
Find out on the announcements how I am using this at:
http://quantlabs.net/membership.htm
Very cool open source project at
http://code.google.com/p/webcurvesim/
NOTE I now post my TRADING ALERTS into my personal FACEBOOK ACCOUNT and TWITTER. Don't worry as I don't post stupid cat videos or what I eat!