Microsoft has added yet another big name to is Windows Security team: Crispin Cowan. These hirings have become old hat at this point, but this one has an interesting twist in that Cowan is renowned as a Linux security expert. He is the brains behind the StackGuard compiler, which is designed to turn out applications that are resistant to buffer overflows. Cowan also was the CTO and founder of Immunix, which produced a hardened Linux OS and was acquired by Novell in 2005.

Here’s what Microsoft’s Michael Howard had to say about Cowan’s hiring:

He’s well published, wicked smart, a non-zealot and brutally pragmatic. In my opinion, AppArmor is shining example of his pragmatism, it’s simple and it works. What excites me the most is he’ll bring a different perspective to the Windows team, and I’m a big believer in stirring the pot! Crispin will work in the same team that worked on User Account Control (UAC) and integrity levels, an area he knows a great deal about.

Cowan is probably as respected as anyone in the security community and he is unafraid to speak his mind. It should be fascinating to see how he works inside the ropes in Redmond and what effect his open-source background will have on the ways things work.