What are the major differences between ANSI C and K&R C?

Question

The Wikipedia article on ANSI C says:

One of the aims of the ANSI C standardization process was to produce a superset of K&R C (the first publishe

Answer 1

Despite all the claims to the contary K&R was and is quite capable of providing any sort of stuff from low down close to the hardware on up. The problem now is to find a compiler (preferably free) that can give a clean compile on a couple of millions of lines of K&R C without out having to mess with it.And running on something like a AMD multi core processor.

As far as I can see, having looked at the source of the GCC 4.x.x series there is no simple hack to reactivate the -traditional and -cpp-traditional lag functionality to their previous working state without without more effor than I am prepered to put in. And simpler to build a K&R pre-ansi compiler from scratch.