The following is a list of some of the tools we have used to create MySQL. We use this to express our thanks to those that has created them as without these we could not have made MySQL what is is today.
From whom we got an excellent compiler (gcc), an excellent debugger (gdb and the libc library (from which we have borrowed strto.c to get some code working in Linux).
For a really great editor/environment used by almost everybody at MySQL AB.
Author of valgrind, an excellent memory checker tool that has helped us find a lot of otherwise hard to find bugs in MySQL.
For DDD (The Data Display Debugger) which is an excellent graphical frontend to gdb).