Recovered from the Wayback Machine.
Tim Bray has an interesting take on the use of AJAX: rather than have your server do the data processing, use AJAX to grab the data and then have the clients do the work:
A server’s compute resources are usually at a premium, because it’s, you know, serving lots of different client computers out there. Lots of different computers, you say; and how busy are they? Not very; your average Personal Computer usually enjoys over 90% idle time. So you’ve got a network with a small number of heavily-loaded servers and a huge number of lightly-loaded clients. Where do you think it makes sense to send the computation?
However, a developers first priority is to do no harm to those using their application. Their second priority is to ensure their pages are accessible by their target audience. If we start making assumptions that the client’s machine is ours to do with what we will, we won’t need hackers to inject harm into our scripts–we’ll do a fine job of it, ourselves.