JDebugTool is a standalone graphical Java debugger built on top of the standard JPDA (Java Platform Debugger Architecture).
Changes
In this release, the Objects, String/To String, and Events windows are now top-level Frames, instead of dialogs. The screen locations and sizes of the top-level Frames in the GUI are now remembered persistently between JDebugTool invocations.
URL: JDebugTool - Graphical Java Debugger