The original version of this document was written by Mark Eichin to give people a handy reference to the many symbols that LATEX supports, especially the math mode symbols. Most of his text and all of his tables were included in the guide that you are holding now.
The rest of the first edition of the guide was written and edited by Nancy Gilman, David Jedlinsky and Mary Vogt, with lots of comments (flamage) from SIPB members and other people who experimented with the early versions of the guide. Robert French perfected this document to produce Revision 1.
Later, Chee Chew, added more changes (with more input/flamage from SIPB members) to produce Revision 2.
Revision 3 was updated by Mark Eichin to
cover the replacement of dvi2ps by the superior dvips,
to acknowledge Athena's support of LATEX, and to include further
SIPB member comments. Subsequent changes have been made by Richard
Barbalace, bert Dvornik, and Chad Brown, with the cheerful support of
many SIPB members and prospectives.
Revision 4 was updated by Alex Rolfe to reflect the adoption of LATEX2eas the default version on Athena.
Thanks to John Kohl and Jean Marie Diaz for getting most of the original TEX and LATEX system running on Athena in the first place; without their efforts, this guide would be useless.
And, of course, thanks to Don Knuth, the author of TEX, and Leslie Lamport, the author of LATEX; they have done an incredible job.