Yahoo’s announcement of Yang’s resignation notes that Yang also resigned from the boards of Yahoo Japan Corporation and Alibaba Group Holding Limited. It also includes this excerpt from a letter Yang wrote to Roy Bostock, Yahoo’s chairman of the board: My time at Yahoo!, from its found to the present, has encompassed some of the most exciting and rewarding experiences of my life. However, the time has come for me to pursue other interests outside of Yahoo! Yang also expressed enthusiasm for the appointment of Scott Thompson as Yahoo CEO two weeks ago. Yang’s resignation crowns a tumultuous f…