Visual debugger with recall of operation history. [Commercial]

By debugtools.com is Java debugger, built on top of the standard JPDA (Java Platform Debugger Architecture). It features an intuitive and graphical Java Swing GUI. [Shareware]

Analyzes program execution and generates a trace and a visualizer. Supports JDK 1.1 and higher. For debugging, understanding, diagnosing. [Non-timeout eval copy]

An experimental debugging tool written in Java which allows "rewinding" and seeing what the values of variables were in the past. Works by modifying bytecode. [Freeware]

A Java monitoring platform. It attaches to Java application, using its own lightweight web server to let view log messages, threads, properties, and runtime statistics. It comes with its own logging API, plus it supports the log4j API and the Java Log...

A debugging tool similar to the Inspector in Smalltalk environments. [Freeware]

A grafical user interface for the java.util.logging package. [Freeware]

A tool for Java developers who are curious about what really goes on inside the JRE (Java Runtime Environment). It provides a view of runtime activity such as system properties and thread activity. [Freeware]