My latest app Frehq uses a sophisticated JQuery ajax technique called promises which is a deferred object that can handle multiple callbacks and relay the success or failure state of each function back to the app as it happens. When you click Submit the program sends out a request to each RSS feed you have selected, simultaneously. As each feed comes back I turn the count indicator red and it’s fascinating to see the sequence they arrive, in real time.
I’ve also implemented a timeout value which stops each process if it exceeds x number of seconds. The default is five seconds, but you can adjust that value with the new slider at the bottom. If any selection exceeds the timer the control turns yellow, the whole thing stops, and you can de-select the slow retrieving feed or bump the timeout value up higher. This gives you control over how much time you’re willing to invest in receiving the content, and the flexibility I’m able to create just blows my old programmers mind!