1. Mega-Extensive TelecommunicATions ApplicATions Language. BBS language for PRODOS 8 on Apple II. 2. The syntax-definition formalism of the Mentor system. Metal specificATions are compiled to specificATions for a scanner/parser generATor such as Lex/Yacc. "Metal: A Formalism to Specify Formalisms", G. Kahn et al, Sci Comp Prog 3:151-188 (1983).