Multiple harmonic sums, multiple zeta values and other related values

In this talk I will survey the historical and recent development in the study of multiple harmonic sums, multiple zeta values and some other related values such as multiple zeta star values and their q-analogs, mainly from the number theory point of view. Starting with Euler's decomposition formula for double zeta values I will conclude with a sketch of the Two-one formula conjectured by Ohno and Zudilin when they were here at MPIM in 2007. Most part of the talk will be accessible to the general
audience.