Dear All, Following the informal announcement at CT08, We are very pleased to announce a conference to celebrate the 60th birthdays of Martin Hyland and Peter Johnstone. How: PSSL Where: Cambridge When: weekend of 4-5 April 2009 The conference will be generously supported by the Morgan Phoa Family Fund and the Department of Pure Mathematics and Mathematical Statistics of Cambridge University. We are making this preliminary announcement well in advance, as We hope that very many people will be able to join us and contribute talks for this event. The website for the conference is at http://cheng.staff.shef.ac.uk/pssl88/ If you have any questions please feel free to contact Eugenia Cheng at e.cheng@sheffield.ac.uk We hope to see you there, Eugenia Cheng Andy Pitts (organisers)