The GNU Debugger allows you to see what is going on "inside" a program while it executes - or what a program was doing at the moment it crashed.

GDB supports C, C++, Java, Fortran and Assembly among other languages; it is also designed to work closely with the GNU Compiler Collection (GCC).

The GNU Debugger Program has four special features that helps you catch bugs in the act:

• It starts your program for you, specifying anything that might affect it's behavior.
• Makes your program stop under specified conditions.
• Examines what happened when the program stopped.
• Allows you to experiment with changes to see what effect they have on the program.

• setting and clearing breakpoints
• examining the stack, source files and data
• examining the symbol table
• altering program execution
• specifying a target for debugging
• how to control the debugger
• how to use canned command sequences
• how to install GDB
• and much more!

About the authors:
Richard M. Stallman, founder of the Free Software movement, is the original author of GDB. Roland Pesch is a professional technical writer. Stan Shebs was a primary maintainer of GDB during the 1990's.