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 published standard), incorporating many of the unofficial features subsequently introduced. However, the standards committee also included several new features, such as function prototypes (borrowed from the C++ programming language), and a more capable preprocessor. The syntax for parameter declarations was also changed to reflect the C++ style.
That makes me think that there are differences. However, I didn't see a comparison between K&R C and ANSI C. Is there such a document? If not, what are the major differences?
EDIT: I believe the K&R book says "ANSI C" on the cover. At least I believe the version that I have at home does. So perhaps there isn't a difference anymore?
There may be some confusion here about what "K&R C" is. The term refers to the language as documented in the first edition of "The C Programming Language." Roughly speaking: the input language of the Bell Labs C compiler circa 1978.
Kernighan and Ritchie were involved in the ANSI standardization process. The "ANSI C" dialect superceded "K&R C" and subsequent editions of "The C Programming Language" adopt the ANSI conventions. "K&R C" is a "dead language," except to the extent that some compilers still accept legacy code.