I just witnessed a beautiful example of web application architecture. After periodically making adjustments to my schedule in Google Calendar the past several hours, I witnessed the user interface change, in real-time, without even refreshing my browser.
For as long as I can remember, any time I would click and drag on my calendar to create a new appointment, a block of time would be selected in gray until I released my mouse button. The time would then be reserved with a solid blue block and I would fill in details about the appointment I just made. Just last week I was thinking, “it would sure be nice if they did a better job indicating the time frame you’re actually blocking off so I don’t have to eyeball it.”
Well, while making one final appointment on my calendar tonight, I noticed that the typical gray selection of time had been replaced with a transparent blue block with the time-frame in it. The time frame and size of the box still adjusted as I moved my cursor down my schedule. When I released the mouse button, things worked as they always have. If this new user experience wasn’t enough to be impressed by, I realized I hadn’t refreshed my browser at all. The new feature just appeared:
And that is one of the wonderful benefits of running an application on the web. Although I’m not sure exactly how they do it, Google has engineered Google Calendar so that they can roll-out changes to the user interface in real-time to users. Real-time connection to Google’s servers through Ajax is all that’s needed–no bulky Microsoft-Office-like update to download and install, not even a browser refresh.
Very impressive.
Ian Lotinsky 
wow.
that’s cool!