You have a good point, but I don't think I asserted that any of those points are correct. I mostly agree with JulianMorrison on this one, although I think somet

You have a good point, but I don't think I asserted that any of those points are correct. I mostly agree with JulianMorrison on this one, although I think sometimes you can see performance bottlenecks coming. If you know an inner loop needs to be faster than your interpreted language can normally do, you might as well write that segment in C or ASM from the beginning. Mercurial still seems to me like a good example of optimization done correctly.