I do know that the new runtime included as part of the JDK 1.3 has introduced some unusual new bugs into development. JRun 3.0, from Allaire, does not like running as an underlying service on Windows NT, when 1.3 is used. The reason? Hotspot doesn't handle some of the logging off events that NT generates, thus killing off the Java process. 'Twould be nice to use an optimizing compiler for JSPs and Servlets.