we did some simple PHP.
AJAX - asychronous JavaScript and XML

Web 2.0

ajax is really just the combination of JavaScript on the client side with e.g. PHP on the server side, communicating with each other asynchronously via XML

Open source software
http://en.wikipedia.org/wiki/Open-source_software

Linux -- a free, open source Operating System

OpenOffice - a free office clone
openoffice.org

talk next time briefly about google docs