SPE is a python IDE with auto indentation&completion,call tips,syntax coloring&highlighting,uml viewer,class explorer,source index,todo list,pycrust shell,file browsers,drag&drop,Blender support.Spe ships with wxGlade,PyChecker and Kiki.
UPS is a source level C, C++ and Fortran debugger with an X windows interface. It's a very light debugger, but is quite efficient and works well. An ANSI compliant C interpreter is included.
Excellent macro based library to see program flow, variables, timings, errors, warnings. "Must have" for C/C++ programmers.
Leaktool : A java memory leak hunting tool using jvmpi.