I deeply regret that, I cannot be present for your birthday celebration at MFPS. But I'd still like to offer my congratulations and express my feelings.
Beginning at least as far back as your Ph.D. thesis, you have steadfastly pursued a quest for the mathematical underpinnings of programming languages. The result has been a series of profound papers, an influential textbook, and two finely educated Ph.D. advisees, all testifying to the belief that the design of programming languages can be a deeply rational endeavor.
Your work is a peculiarly deep application of mathematics - not the usual approach of translating a problem into mathematics and then using clever theorems, but rather the seizing of the underlying organizing principles of mathematics (especially category theory) to organize programming. It is an inspiration to all of us who aspire to mathematically elegant languages that support, rather than impede, the art of programming.
In addition to being a leader, however, you are a valued comrade - a source of helpful encouragement and advice, invariably modest and open-minded.
On your sixty-fifth birthday, I believe I speak for many when I thank you for your ideas, your leadership, and your friendship.
All the best,