thanks for visiting. behind the tabs above are most of my papers, some of the slides from my talks or courses, and on the right are links to the recordings of some recent ones. the publication details for the papers are in this BibTeX base.
recent papers:

Quotients in monadic programming: Projective algebras are equivalent to coalgebras (with PeterMichael Seidel) LICS 2017

Monoidal computer III: A coalgebraic view of computability and complexity (with Muzamil Yahia)
a recent course:
Synopsis. What is Computer Science about? What is a computer? What is a recursive function? Why is the Halting Problem undecidable? What is a supercompiler? Answers in pictures.
some old web pages with older stuff which i didn’t transfer:
 at Kestrel Institute (19992009)
 at Oxford University (20082012)
 Cloudfactory (up to 2006)
 Royal Holloway (20102013)