Bert Bos was, in 1994, one of the original authors of CSS. He joined W3C in 1995 to set up W3C’s internationalization activity and was part of the groups that created HTML and XML. He is now coordinator for W3C’s style sheet and math activities. Bert studied mathematics in Groningen, The Netherlands, and holds a PhD from that university. He is co-author with Håkon Wium Lie of the book “Cascading Style Sheets: designing for the Web” (3rd ed., Addison-Wesley, 2005)