the aim of the talk is to describe the overconvergent de rham-witt complex. it is a subcomplex of the de rham-witt complex and it can be used to compute monsky-washnitzer cohomology for affine varieties, and rigid cohomology in general. (all our varieties are over a perfect field of characteristic p.) we will begin by reviewing monsky-washnitzer cohomology and the de rham-witt complex. next we will define overconvergent witt vectors and then the overconvergent de rham-witt complex. as time permits, we will say something about the proof of the comparison theorem between monsky-washnitzer cohomology and overconvergent de rham-witt ohomology. this is joint work with andreas langer and thomas zink.