A concept which addresses the social aspects of *(user interface)s. It is a stream of _(information) chunks to organize the way a person deals with other people, in much the same manner as an electronic diary. The chronological arrangement is key, but the information can be organized in many other ways.

The basic unit of information is the chunk, which consists of content,
time of occurrence and other attributes.  However, all chunks are
relative to a Lifestream and agent (the minimal case being a unique
chunk or chunk/stream/agent triple).  Chunks can belong to many
Lifestreams and have many associated agents.  Many chunks do not have
names.  In general, naming is eschewed for attributes; naming is seen
as costly to the user and often of little benefit, whereas many
attributes can be inferred from context.

Substreams (also called Lifestreams) are the basic organizational
mechanism.  Substreams are picked out of a parent Lifestream based on
a set of search criteria.  They live until they are killed, and update
dynamically as more chunks are found or created.  They can also be
hidden.

Hiding and killing are rarely done.  More common is for a substream to
fade into "the past."  Past, present and future are relative to the
system clock, which can be "dialed back/forward" to assume a new
temporal viewpoint.  This permits scheduling, among other things.

"An agent," say the designers, "is tied onto each infochunk the way a
helium balloon might be tied down to a chunk of plastic-sort of."
Agents are the basic means of behavioral organization.  They are
responsible for organizing and updating substreams and provide a way
for a Lifestreams terminal, or viewport, to communicate with outside
systems like email.  They can do things like scan other streams or
systems for interesting events, or cooperate with other agents in
producing present events or scheduling future ones.

<ul class="links">
  <li>_("The 'Lifestreams' Approach to Reorganizing the Information World"
  | http://www.cs.yale.edu/Linda/lifehype/life.html)
  (_(".ps" | http://www.cs.yale.edu/Linda/life/life.ps)).</li>
  <li>_("Lifestreams: An Alternative to the Desktop Metaphor"
  | http://www.acm.org/sigchi/chi96/proceedings/videos/Fertig/etf.htm)
  (_(CiteSeer|http://citeseer.nj.nec.com/23100.html)).</li>
  <li>_("Scopeware" | http://www.scopeware.com/), the commercial spin-off.</li>
</ul>