Aaron J. Seigo: backward compat is good, bad
i read ian murdock's blog entry on the importance of backwards compatibility i found myself at once agreeing and wincing.
i agree that backwards compatibility is down right important, particularly for our users not to mention third party developers. the example ian used from joel's blog about sim city causing microsoft to patch their allocator so it behaved differently just for that one app (!!!) is so amazingly bad, though, that it's a bit unfortunate. a number of the comments on his blog got sidetracked by this poor choice of an example.
however, backwards compatibility, like most things in life, is neither all good or all bad. (dualism: blech!) with all the upside of it, there's also the drawbacks that come with it. namely increased engineering costs due to increased complexity of both development and testing, greater exposure to security risks and a real stunting of innovation since you can't just change things willy nilly.
we all want quickly developing, solid and innovative software ... but we also want backwards compatibility. how do we get both?