log4js has moved to Github: http://stritti.github.io/log4js.
JDumpViewer is a graphical tool used to analyze Java thread dumps
JTombstone is a program for finding dead code in your Java programs. It reports on dead code at the method level, by processing Java class files. No source code is needed to use it. JTombstone is a Java program and requires JDK 1.4 or later.
SpyCat is Eclipse plugin for monitoring requests to Tomcat servlet container in realtime. Keywords: Tomcat, servlet, http request, server.xml, SWT, JFace, RMI
x4juli is an e(x)tension for(4) the (j)ava util(u) (l)ogging implemantion. It is a port of major log4j features (RollingFileHandler, PatternLayout, Filters). It includes a native implementation of "Jakarta Commons Logging" and "slf4j".