JBookTrader is a "sister" project to JSystemTrader. Both are fully automated trading systems, both are open source projects, and both are intended for Java developers. The difference is that JBookTrader is specifically designed to trade based on market depth changes. JBookTrader project & download page: http://code.google.com/p/jbooktrader/ JBookTrader discussion group: http://groups.google.com/group/jbooktrader