This timely collection of expository papers highlights progress and new directions in Hopf algebras. Arising from the MSRI workshop on Hopf Algebras in October 1999, some papers consider Hopf versions of classical topics, such as the Brauer group, while others are closer to recent work in quantum groups. In particular, there are articles on recent progress in classifying finite-dimensional Hopf algebras, both in the semisimple case and in the pointed case. The volume also includes an updated version of Mitsuhiro Takeuchi's article "A short course on quantum matrices", now a standard reference in spite of its relative lack of availability.