There is a very active network of improvisational theatre groups in Paris.
I trained for a year and a half with "The Impro Academy" before setting up a show in 2010 with some ex-students of the Impro Academy. We were "les cinq à sept". We dissolved our group shortly after the show to persue other goals, but I still play on a guest basis in other troops.
There are two main types of improvisation circles: the 'storytelling' kind, where the format can be short as a sketch or as long as a play, and the 'match' kind, where opposing teams play for the audience to win points.Improvisation is a different challenge to script Theatre, and a different type of experience when you go to watch it.