HTTP has been a successful hammer
Jean-Louis brought up the issue of the limits of HTTP, which has been also on my mind since I realized the X in XMPP. I very much agree that HTTP is highly overused; it’s the ‘hammer and nails’ syndrome once again. Of course, it’s easy to waste a lot of time by constantly jumping between all the different technology-bandwagons, but evolution needs to happen eventually. My hopes were high on that Flex/OpenLaszlo would have surpassed AJAX, as HTML is not a user interface language! MXML (of Flex) is, and there’s a world of difference in that. Similarly, HTTP is not a two-way/push protocol, what some folks are trying very hard to work around. XMPP is two-way and, thus, complicated callback protocols wouldn’t be needed if XMPP was used as the SOAP transport [think about it].
It could be interesting to see some statistics, but I guess RSS polling isn’t really taking up significant server time nor bandwidth yet, with caches and all. However, I believe this can change quickly if the polling interval is reduced from (sub-)hours into minutes – and with the upcoming RSS popularization by IE7. HTTP really is not viable for such scenarios – very inefficient use of resources, indeed.
The ‘long tail of technology’ is definitely a smart metaphor. I like it.