"A Triumph of Engineering over Design"

Jim Horning has a nice cautionary tale about the over-zealous application of auto-correction in one of the IBM PL/I compilers:

It always converted its input into legal PL/I; whenever it encountered an error, it modified the program to a form it could deal with; and it always executed the compiled result, no matter how many errors had been encountered.

I suppose its creators thought they were being helpful in covering up the users' mistakes...