Open strings and noncommutative geometry of branes on group manifolds

In this letter we review some recent work on the noncommutative geometry of branes on group manifolds. In particular, we show how fuzzy spaces arise i n this context from an exact worldsheet description and we sketch the const ruction of a low-energy effective action for massless open string modes. Th e latter is given by a combination of a Yang-Mills and a Chern Simons like functional on the fuzzy world-volume. It can be used to study condensation on Various brane configurations in curved backgrounds.