|EL1 - Extensible Language One. An extensible language by
B. Wegbreit of Harvard ca 1974. EL1 is internally somewhat
Lisp-like, but fully typed with records and pointers. The
external syntax is ALGOL-like and extensible, supporting
user-defined data structures, control structures and
operations. The parser is table-driven, with a modifiable
set of productions. Used as the basis for the ECL
["Studies in Extensible Programming Languages", B. Wegbreit, Garland. Pub 1980].