The workbench runs on most Unix systems (Sun, DEC, HP...) and under DOS on PC's, although most of our experience is on Sun's. It does not have a teletype interface--it only runs as a graphical program. It requires at least 16MB of ram on UNIX and 8MB under DOS, plus 40 or more MB of disk (for program storage and swapping).
Xerox makes the system available at no cost by anonymous FTP under a license that allows for noncommercial uses of the workbench in research and education. The system and its documentation (in Kaplan and Maxwell 1996) are located at parcftp.xerox.com in the directory /pub/lfg/.
For further information, contact kaplan@parc.xerox.com.
References:
Kaplan, Ronald M. and Joan Bresnan. 1982. Lexical-Functional Grammar: A formal system for grammatical representation. In Joan Bresnan, editor, The Mental Representation of Grammatical Relations. The MIT Press, Cambridge, MA, pages 173--281. Reprinted in Dalrymple, Kaplan, Maxwell, and Zaenen, eds., Formal Issues in Lexical-Functional Grammar, 29--130. Stanford: Center for the Study of Language and Information. 1995.
Kaplan, Ronald M. and John T. Maxwell. 1996. LFG grammar writer's workbench. Technical report, Xerox PARC.