http://www.gnu.org/software/ddd/


GNU DDD is a graphical front-end for command-line debuggers such as GDB, DBX, WDB, Ladebug, JDB, XDB, the Perl debugger, the bash debugger bashdb, the GNU Make debugger remake, or the Python debugger pydb. Besides ``usual'' front-end features such as viewing source texts, DDD has become famous through its interactive graphical data display, where data structures are displayed as graphs.