Cxref is a program that will produce documentation (in LaTeX, HTML, RTF or SGML) including cross-references from C program source code. It works for ANSI C, including most gcc extensions. The documentation for the program is produced from comments in the code that are appropriately formatted. The cross referencing comes from the code itself and requires no extra work.

Fuzz is a tool for testing other software. It does this by bombarding the program being evaluated with random data.

Insight is a graphical user interface to GDB, the GNU Debugger written in Tcl/Tk by people working at Cygnus Solutions.

Open source, kernel-level debugger for Linux with the look and feel of Window's SoftIce

Catalogs system events in minute detail, and allows a user to determine exactly what is transpiring on his system, down to the microsecond.

This kernel allows developers to write and debug code using the normal process-level tools, like gdb, gprof, and gcov.

An open-source memory debugger for x86-linux.

Coredump debugging software which works on Linux(ELF) and Mac OS X(mach-o). It helps the programmer to obtain essential information about the abnormal termination of a process or a thread.