This web-based network and systems management platform competes with commercial products like HP's OpenView and IBM's Tivoli. This in-depth presentation looks at the OpenNMS project, architecture, and complementary technologies such as PostgreSQL, Apache's Jakarta Tomcat server (Servlets and JSPs), Sun's JSDT, and many technologies within the Apache XML project (Xerces, Xalan, FOP, SOAP, and Crimson).