I am currently writing an implementation of the C99 programming language as a basic language for the MPS language workbench. I call this implementation c-base, because it is intended to be used as a target language for code generation, much like MPS' Java-like base-language.
I created the model of this MPS language according to the C99 standard grammar. Thus, I had to dive into its documentation and I have found a number of surprising features and properties of the C99 programming language. Not all of them are important, but if you want to be nitpicker in the next C discussion, here is your ammo ;-)
So, did you know, that