KDbg is a graphical user interface to gdb, the GNU debugger. It provides an intuitive interface for setting breakpoints, inspecting variables, stepping through code and much more. KDbg requires KDE but you can of course debug any program.

Features include the following:
* Inspection of variable values in a tree structure.
* Direct member: For certain compound data types the most important
member values are displayed next to the variable name, so that it is
not necessary to expand the subtree of that variable in order to see
the member value. KDbg can also display Qt's QString values, which
are Unicode strings.
* Debugger at your finger tips: The basic debugger functions (step,
next, run, finish, until, set/clear/enable/disable breakpoint) are
bound to function keys F5 through F10. Quick and easy.
* View source code, search text, set program arguments and environment
variables, display arbitrary expressions.
* Debugging of core dumps, attaching to running processes is possible.
* Conditional breakpoints.