Do Open Source Eyeballs Really Work?
One of the most contentious areas in computing is whether open source is more or less secure than closed source systems. Open source is open for everyone – including the black hats – to poke around and find the bugs, but it's also open for anyone skilled enough to fix them. Closed source is (theoretically) harder to peek into, but (practically) impossible to fix unless you work for the company that wrote it.
Here's some nice empirical evidence that many eyeballs looking at open source code *do* make a difference...
On Open Enterprie blog.