This article gives an introduction to the changes made in the 2008 Update of the OECD Model and Commentaries. After introductory remarks, the article discusses some of the changes pertaining to e.g. Art. 4 (Residence), the alternative services permanent establishment rule (Art. 5), the attribution of profits to PEs (Art. 7), the treatment of real estate investment trusts, Art. 12 (Royalties), Art. 24 (Non-discrimination) and mandatory binding arbitration (Art. 25(5)). The article concludes that, on any measure, the changes represent a significant development in the OECD Model.