This is an independent implementation of Objective C - independent
of Stepstone's, NeXT's, GNU's (Free Software Foundation) or SunSoft's
Objective C implementation.

Like the GNU compiler, the "objc" grammar is written in YACC.  The lexical
ananlyzer is written in LEX, and the compiler itself in the Bourne
shell and in Objective C.  (the optional Objective C link editor is
written in AWK).

WWW: http://users.pandora.be/stes/compiler.html