The files in this directory are the current distribution of the LLG official Lojban parser, in source form and MS-DOS executable.
Basically, there are two files. parser.zip contains the MS-DOS executable, whereas parser.shar.gz contains the source code. To compile the parser from the source code, just say "cc -o parser *.c"; there is no Makefile. The code is in K&R C, but should compile all right using an ANSI compiler. If you have trouble unpacking the ZIP file, use PKZipFix to convert it to MS-DOS ZIP format.
Both versions contain the 'yacc' grammar, the current E-BNF grammar, and a list of technical fixes updating the 2nd baseline grammar. You can process the 'yacc' version with yacc or bison, but do not attempt to use the resulting y.tab.c file in the parser — the provided grammar.c has been extensively hacked both before and after 'yacc'ing to make it work in the parser.
Much newer version 3.0 resides on John Cowan's site, look for file parser-3.0.00.tar.gz No idea about it's official status although.