Try the open-source Natural Language ToolKit http://nltk.sf.net
Screenshots of context-free grammar and parsers: http://nltk.org/index.php/Screenshots
To run the graphical simulations whcih produced these screenshots, download and install NLTK, see http://nltk.org/index.php/Getting_Started
then follow the instructions to run the demos, see
http://nltk.org/index.php/Getting_Started#Running_NLTK.27s_Graphical_Demonstrations
This *should* work, but the graphics use python linked to a C API so if it doesnt work it may be because you have the wrong version of python/C ... I agree that ideally a web-browser applet would be ideal for demos as totally platform-independent.
good luck!
Eric Atwell, Leeds University
On Thu, 10 Apr 2008, stefano federici wrote:
> Dear collegues,
I would like to be able to show to my students how a context-free grammar does work. I don't need an optimized parser for context-free grammars, but I guess an applet with graphics or similar simulator (best if opensource) would do the trick.
Thanks for your help
Stefano Federici ------------------------------------------------- Università degli Studi di Cagliari Facoltà di Scienze della Formazione Dipartimento di Scienze Pedagogiche e Filosofiche Via Is Mirrionis 1, 09123 Cagliari, Italia ------------------------------------------------- Tel: +39 349 818 1955 Fax: +39 070 937 1870
-- Eric Atwell,
Senior Lecturer, Language research group leader, School of Computing,
Faculty of Engineering, UNIVERSITY OF LEEDS, Leeds LS2 9JT, England
TEL: 0113-3435430 FAX: 0113-3435468 WWW/email: google Eric Atwell