From its roots in Commedia dell'arte, improvisational theatre has evolved into a flourishing independent art form. On TV it's been popularized by the British and USA show "Whose Line Is it Anyway?". Finding a niche somewhere between scripted theater and sketch comedy, improv appears in a multitude of incarnations. Competitive improvisation, where 2 or more teams play against each other, the audience or a jury determining the winner, is presented by groups like "ImprovOlympics", "TheaterSports", and "ComedySportz". Comedy/Satire Improvisation comes in either short or long form. Short meaning that a troupe presents a performance comprised of a series of diverse, audience driven sketches. Long form usually means that the company presents an evening long improv losely structed around an initial audience suggested theme/plot/cast of characters. Playback theatre is an original form of improvisational theatre in which audience or group members tell stories from their lives and watch them enacted on the spot.