Open vs. Closed

There is no better way to start an argument among a group of developers than proclaiming Operating System A to be "more secure" than Operating System B. I know this from first-hand experience, as previous papers I have published on this topic have led to reams of heated e-mails directed at me - including some that were, quite literally, physically threatening. Despite the heat (not light!) generated from attempting to investigate the relative security of different software projects, investigate we must.