The Jakarta Apache Project has released Tomcat 5.5.0, an open source servlet container for the Apache web server and the official reference implementation of the Java Servlet API and Java Server Pages (JSP). "Tomcat 5.5 is designed to run on J2SE 5.0 and later, and requires configuration to run on J2SE 1.4....In addition, Tomcat 5.5 uses the Eclipse JDT Java compiler for compiling JSP pages. This means you no longer need to have the complete Java Development Kit (JDK) to run Tomcat, but a Java Runtime Environment (JRE) is sufficient. The Eclipse JDT Java compiler is bundled with the binary Tomcat distributions. Tomcat can also be configured to use the compiler from the JDK to compile JSPs, or any other Java compiler supported by Apache Ant." The announcement didn't mention anything about the versions of servlets and JSP supported, so I assume this still implements version 2.4 of the Java Servlet API 2.4 and version 2.0 of Java Server Pages like Tomcat 5 did. The version numbering is funky. This is really more like an alpha release and is not considered to be ready for production.
For those who prefer to bleed a little less, the Jakarta Apache Project has also released Tomcat 5.0.28. "This release addresses a number of bugs and contains updated documentation, status, and dependencies."