While I agree with Kernighan that Pascal is not my favorite programming language, UCB Pascal is my favorite compiler because of its spectacularly good syntax diagnostics. The diagnostics are automatically generated, so they have a completely consistent style and never go down rabbit holes trying to explain an error. The UCB trick is to report the exact spot where LR parsing chokes and suggest a canonical alternate token that allows progress. This simple strategy is startlingly effective; the compiler taught me Pascal in an evening. It occurred to me that Pascal would be a suitable language in which to express a certain algorithm. Having skimmed the Pascal report a year or more earlier, I knew it was a pretty typical language, so I grabbed a sample program from somewhere and plowed ahead. I made mistake after mistake, but every diagnostic was instantly suggestive. By the end of the session I had a polished working program. In due time it was accepted for publication. Doug