C89 did: • FILE* was a big I/O abstraction that C did not have before. With Unixes and MS-DOS there were file handles, but many other platforms had nothing lik

C89 did: • FILE* was a big I/O abstraction that C did not have before. With Unixes and MS-DOS there were file handles, but many other platforms had nothing like that. • That there was a clear idea of what kind of operations were well-defined was a pretty big deal. Remember, all there was before was K&R to go off as a reference, or maybe you had access to the Portable C Compiler. It was also a time where you had a lot more oddball architectures. • void return types and parameters. There was no idea of a procedure in early C, only functions with useless return values. And of course more. There are definitely worse cases of ISO standards than C and C++. Both are noticably better out of it.