One of the
alien civilisations created by
Vernor Vinge in the novel
A Deepness in the Sky. They are human, but they lived on a particular
planet, where there was a
plague that almost wiped out their entire civilisation. This plague basically turned the brain into mush by making parts of the brain overactive. This event, called The
Emergency hence their name, completely led to a
restructuring of their civilisation in a way that mirrors this emergency, becoming very
feudal and
Machiavellian. They are generally depicted as "bad guys"; although it is clear that they are bad as a result of their history.
In fact, what happens is that they never quite destroy the virus that brought about The Emergency; rather they learn how to control it and learn that it can be used to enhance the mental faculties of a person in a particular area. The only drawback is that the person affected in this way becomes autistic and only interested in the faculty that was enhanced, and essentially loses their soul. This process is called being Focused.
They conquer other civilisations so that they can be fodder for the Focus. They also figured out that you can organise Focused people into a computational structure, essentially creating a computer out of those people that they had conquered.
The Emergents used these computers, for example, to work out how to manipulate other civilisations politically.