Categories, Software and Meaning

I am delighted to be able to share in celebrating Ugo's birthday, if not with a formal paper then at least with some loosely-knit philosophical ideas. I have worked on ideas similar to Ugo's for most of our careers. Ugo had much to do with the stream of expert Italians, many now well-known, who travelled from the warmth of Pisa to the romantic but cooler climate of Edinburgh, often to launch their careers with a PhD there. Going further back, I remember with excitement the meeting on parallel processes at Pisa in 1973, organised I believe by Ugo, the first concurrency conference I ever attended.