A category of technologies and services that manage inbound and outbound communications, on multiple devices, based on a person’s availability, device capabilities, and preferences. Presence, in a sense, is the “instant: in “instant messaging,” because its what knows when you’re attached to the network, so you can be pinged, live.
Presence, as a technique, strives to be the answer to three questions: Are you on the network? How are you on the network (cell phone? PC? Gadget?) Are you available for communications at this time?
Presence, as a technology, grew from the world of Session Initiation Protocol, or SIP — the underbody of voice services such as Vonage, AT&Ts CallVantage, and Verizons Broadwing.
When it grows up, presence will be like instant messaging and buddy lists — except broader, across more devices, and with more than just text. It’ll do things like finding you, by ringing all your numbers, text messaging all your devices, and IMing you anywhere youre logged in, when it’s someone you really, really, really want to reach, you no matter what — or doing exactly the opposite, when it’s anyone you don’t want to reach you, no matter what.
So far (2005), it’s the latter feature thats working for presence-enabled customers: One of the most popular presence applications is “do not disturb,” which makes people invisible to incoming messages.