In the excellent "How-To: Z Catalog Tutorial" Amos refers us to the "Z Class Tutorial". I think Z Classes are just what I want, but I can't find it. Does anyone know where it is? While I am at it I will ask if I am after the right approach. I am getting back into Zope after a few months away from it due to a job change. So much has changed! I want to make a contact manager. Basically names and addresses and phone numbers, etc. I was thinking about mySQL since I have used it before but I need to implement it on Windows. I would like to be able to reuse it on Linux so I don't want to get into any platform specific database. I started to look at Gadfly but then I came across mention of Z Classes. Are they robust enough for a couple of thousand entries? Can I cross reference say contacts and companies stored in two separate Z Classes? Thank you, Phil. PS please reply to me as well as the list as I only receive the digest.