Last night's AJAX panel discussion hosted by the MIT/Stanford VLAB prompted some thoughts on where browser technologies are going. One of the points I made in the discussion was that AJAX was just a technology for building the client side of a client-server application. It's an important technology for doing so because it has achieved a ubiquity that other client-side application development technologies have failed to achieve. What we've done is create an application that is ubiquitous (the Web browser), and that application has a way of downloading and running code within its own contained environment.
This is a very important point that I don't think most people get. When you visit an AJAX enabled Web site, you are downloading and running an application on your PC. That application just happens to sit within a browser, and does not require going through your operating system to install.
What this means is that Web browser programming model will continue to evolve to make the process of developing downloadable client-side applications that run within the browser easier. The Web browser is a cross-platform UI/client platform. How long before "Web" applications are stored and run locally from your Web browsers "cache" without the need for any Internet connectivity? It's not that far off, and sounds a lot like a downloadable client, doesn't it?