TBNF is an acronym for the phrase, "Translational BNF". BNF refers to Backus Normal Form which is a formal grammar notation used to define the syntax of computer languages, such as Algol, Ada, C++, COBOL, FORTRAN, Java, Perl, Python, and many others. TBNF goes beyond BNF and Extended BNF (EBNF) grammar notation because it not only defines the syntax of a language, but also defines the structure of the abstract-syntax tree (AST) to be created in memory and the output intermediate code to be generated. Thus TBNF defines the complete translation process from input text to intermediate code.
The TBNF concept was first published in April 2006 in a paper at SIGPLAN Notices, a special interest group of the ACM. See the TBNF paper at ACM.