What is devised performance?
Good question. Many answers. The simplest? Devised performance is a way of creating original work in which the hierarchies between roles (i.e. actor versus director versus designer versus choreographer) are blurred. Devised performance is made by an ensemble of creators, who each contribute to the creative process. In most places, this is just theatre! But in the U.S., we tend to make it a distinct category.
There are many, many different ways of going about the ensemble-based creation of new work. But it might not be as foreign as we tend to make it these days. Heck, Shakespeare was a deviser! He was part of a company of actors who each lent their own contributions to the writing of his plays, and he in turn wrote specifically for them. He does seem to get a lot of credit for that...
If you want to learn more about contemporary devising processes, check out Pig Iron Theatre Co., the TEAM, The Civilians, Kneehigh Theatre, and many, many more. Or you can check out this article on Howlround.