When	What
1972	Creation of C by Dennis Ritchie
1973	Re-implementation of the Unix kernel
1978 C78	first edition of the book The C Programming Language by Brian Kernighan
	and Dennis Ritchie and improvements of the language (functions returning struct)
1989 C89	First standardization of C, locales (taking into account user's languages)
1999 C99	inline functions! complex numbers! variable-length arrays!
2011 C11	generic macros, multi-threading in the standard