Selective information dissemination
millions of subscribers and thousands of publishers
potentially high event rates (100+ / sec)
variable event sizes (web page(s) - attr-val. pairs)
subscriptions are volatile, many updates and changes (e.g., 100+ / min)
simple subscription languages suffice
notification rate (e.g., 50 - 100 / sec)
reliable & unreliable notification semantic
notifications propagated via e-mail, wap, TCP, RMI, UDP, http