kdb is a debugger that is part of the linux kernel and provides a means of examining kernel memory and data structures while the system is operational. Additional commands may be easily added to format and display essential system data structures given an identifier or address of the data structure. The current command set allows complete control of kernel operations including single-stepping a processor, stopping upon execution of a specific instruction, stopping upon access (or modification) of a specific virtual memory location, stopping upon access to a register in the input-output address space, stack tracebacks for the current active task as well as for all other tasks (by process id), instruction disassembly, et. al.