JSwat is a graphical Java debugger front-end, written to use the Java Platform Debugger Architecture and based on the NetBeans Platform. JSwat is open-source software and is freely available in both binary and source code form. Its features include sophisticated breakpoints; colorized source code display with code navigator; byte code viewer; movable display panels showing threads, call stack, visible variables, and loaded classes; command interface for more advanced features; and Java-like expression evaluation, including method invocation.