Mesa (the Language)
The language name was a pun based upon the programming language catchphrases of the time, because Mesa is a "high level" programming language.
Mesa is an ALGOL-like language with strong support for modular programming. Every library module has at least two source files: a definitions file specifying the library's interface plus one or more program files specifying the implementation of the procedures in the interface. To use a library, a program or higher-level library must "import" the definitions. The Mesa compiler type-checks all uses of imported entities; this combination of separate compilation with type-checking was unusual at the time.
Please see J.G. Mitchell, W. Maybury, R. Sweet (1978): Mesa Language Manual. XeroxParc CSL-78-1