Everybody is probably already familiar with the Heartbleed bug in OpenSSL that was disclosed this week. I saw two explanations that really impressed me with their clarity. The first was Randall Munroe’s XKCD comic. In a few panels, it illustrates exactly what the problem is. The second is for those who prefer text, and was written by Rusty Foster, formerly of Kuro5hin, who did a great job of explaining Heartbleed in the New Yorker.
Brent Simmons wrote up one possible implication of the bug, which is that writing software in C is no longer worth the risk.