GNU Data Display Debugger DDD is a debugger with built-in visualization capabilities. Elements are presented as graph nodes and edges. Also offers alias detection to recognize links to same object, e.g. circular lists. Requires no additional tool, programming or recompilation provided the compiler was started with -g option. Also includes GNUPLOT functionality for plotting scalars, 1D or 2D arrays, may animate plots. Display is updated at breakpoints. Dynamic animation possible by linking breakpoint with continue statement: stop, update display, continue when breakpoint reached - works as a data collector. Offers session saving and plot data export.