These are notes in preparation for a talk I'll be giving to LUNA.

Client / Server Structure

The basic structure of the web is one of clients and servers. A web server sits around waiting for someone to request a document from it. That someone is a client. The basic steps are these:

Client requests document ("http://www.yahoo.com/")

Server receives request

Server looks for document and returns it to the client

Client displays the document

Turning this into an interactive situation is quite easy, really. All we have to do is modify step 3. Instead of the webserver finding and returning a document, we have the webserver execute a program and we return the result. And voila! We now have a web-based application.

There is a hitch with this simple method of allowing a client to request the result of a computation through a webserver. In a word -- "state".