This is part of the GnuCompilerCollection and is also compatible with other debuggers.
See http://www.gnu.org/software/ddd/Moved from DeeDeeDeeddd, is a free graphical debugger front-end for *nix that can leverage any of the popular command-line debugger utilities.
I'm wondering if anyone here has had experience with it. Good? Bad? I plan to give it a try, myself... my main mechanism of 'debugging' has always been optional runtime-tests and trace-statements along with careful analysis of code. I've been wondering if this would make me any more productive.