Codeslasher
Looks very impressive...
mmozeiko
There is DDD debugger which is frontend for GDB and others: https://www.gnu.org/software/ddd/
Its focus is representing data structures visually in various ways. For example, here's how linked lists look like in DDD: http://www.cs.angelo.edu/~mmotl/2...dd/html/PICS/ddd-print-output.png