I don't think it is -- it's full of the kind of features (complicated condition expressions, long chains of elses, hard-coded numbers) that, when I find myself writing them, suggest that I'm approaching the problem in the wrong way, because previous experiences make me associate that kind of code with lack of generality and corner-case bugs.
which is what most diff tools use. It is a simple and clear algorithm with no special cases once you get your head around it. It works in O(NxM) time, which seems like a reasonable lower bound (you need to compare everything to everything else to have a chance of getting the best alignment) although there are ways to do better with constraints.
(I remember one for gene alignment which broke N and M in two, recurse 4 times on each pairing, and then had a quick-ish way to put those together again. Can't remember the details though!)