This is to tell, or remind, readers about the Web-based interactive category-theory demonstrations I have on my site. Perhaps of interest to new students now an academic year is starting. They're at http://www.j-paine.org/cgi-bin/webcats/webcats.php . After some preamble, this page contains a form divided into sections. Each section generates a particular construct in the category of finite sets: e.g. a colimit, equaliser, or initial object. You can input sets and arrows, or let the demo choose its own. The output includes a diagram, and text explaining it. Cheers, Jocelyn Paine http://www.j-paine.org +44 (0)7768 534 091 Jocelyn's Cartoons: http://www.j-paine.org/blog/jocelyns_cartoons/ [For admin and other information see: http://www.mta.ca/~cat-dist/ ]