Some languages have several branches of themselves.
For example there is Old English, current English (modern english?), combined Old and current english.
There is C99, C Some Other Year, Ansi C, K&R C, Ada 95, Ada Something Else, Standard Pascal, Apple Pascal, Some Other Pascal, Common Lisp, Some Other Lisp.
We could call them implementations, but they are languages themselves... some are branches of a language, some are Year Specific Languages, some are older versions of a language, some are modified versions (greatly or insignificantly) etc. That's why they are Language Languages.
See original on c2.com 