I was chatting with Jason "Argos" Hughes after the Skillsmatter event last week, and he said something I think is really quite brilliant, so I hope he doesn't mind if I quote him here and expand on his ideas a little.
We were discussing the merits of various different platforms and programing languages, and he said "knowing a language inside-out doesn't make you a better programmer, any more than knowing a lot about a particular car makes you a better driver".
That comment has been going round and round my head ever since, and I think that's one of the most insightful metaphors about programming languages that I've heard. Anyone who's owned a car will know that every make and model - and every individual example of a particular model - has its idiosyncrasies and quirks. I drive a slightly knackered Vauxhall Tigra. On this particular car, I know that I need to replace the cam-belt every 40,000 miles or Really Bad Things might happen. I know that I need to clean the gunk out of the frame around the back window otherwise it fills up with rainwater; I know where the little lever to adjust the seats is, and where all the various controls and switches are, and how to check the oil and change the headlamp bulbs.
None of this makes me a good driver. In fact, it has absolutely nothing to do with my driving ability. Beyond a basic familiarity with a vehicle's controls and signals, the Highway Code has very little to say about the quirks and idiosyncrasies of particular cars. On the other hand, it has rather a lot to say about stopping distances, speed limits, lane discipline, the importance of maintaining awareness of your surroundings and communicating your intentions clearly to other road uses. In other words, being a good driver boils down to discipline, restraint, awareness and communication - your choice of vehicle is largely irrelevant. Good drivers are good whatever they're driving, and the choice of car alone can't turn a poor driver into a good one.
I think there are strong parallels here with software development. Good coders are like good drivers; they'll work within the safe parameters of whatever technology they're using, exercise restraint and discipline in the application of that technology, and rely on awareness and communication to make sure that they're doing doesn't create problems for other people.
Programming interviews can easily degenerate into a pop-quiz about the characteristics of a particular language or platform, but maybe we should be approaching them more like a driving test - even to the extent of letting the candidate demonstrate their problem-solving capabilities using whatever languages and tools they're comfortable with, and then discussing the results in terms of clarity, effective communication, restraint and awareness. Even though we're a .NET shop, I can see how a developer who can create elegant solutions in Ruby or Java and explain clearly what they've done might be a better .NET programmer than somebody who knows every quirk of C# and ASP.NET but can't demonstrate those core qualities of discipline, restraint, awareness and communication.