Gael Delalleau is a speaker and engineer who has presented at CanSecWest, I-4, SSTIC.
In 2005, he presented "Large memory management vulnerabilities" and the first stack-clash exploit in user-space (against mod_php 4.3.0 on Apache 2.0.53): http://cansecwest.com/core05/memory_vulns_delalleau.pdf