Formal language
set of strings of symbols that may be constrained by rules that are specific to it; words whose letters are taken from an alphabet and are well-formed according to a specific set of rules
recursively enumerable language
theory
communicating sequential processes
L-system
Enterprise Privacy Authorization Language
eXtensible Server Pages
modeling language
Universal Networking Language
elocution
Simple Knowledge Organization System
Guarded Command Language
ADEPT
Semantic Web Rule Language
architecture description language
machine code
computer language
ontology language
indexed language