Bill’s Messages to the Categories list

The Categories List, which continues today, is an email distribution list, which has played an important role in improving communication between researchers, and broadening discussion on important developments in category theory. Together with the yearly conferences, often known as the CTs, and more and more smaller conferences and new journals, the Categories List has been a longstanding feature of the growing worldwide category theory community. Bob Rosebrugh is a founder of both the Categories List and of the on-line journal Theory and Applications of Categories, commonly known as TAC. Bob served as managing editor of TAC for 25 years. An appreciation of Bob’s many contributions can be seen in the foreword to TAC’s Rosebrugh Festschrift.

When asked about the importance of Bill’s Messages,  Bob said: “It was a great resource for the list that Bill (and others) were so very generous in their responses to queries on the list. As Matías and I found when we aggregated Bill’s emails, they have a lot of information that is not available elsewhere. While the list posts are only organized by the order in which they arrived, that makes it possible to follow the evolution and growth of ideas over time. The subject is richer for this contribution from Bill, just one among so many others.”

How should we make use of this interesting compilation of Bill’s emails?

Bob suggests: “Not many will read through the messages in order as presented. Fortunately even pdf files allow searching, so that posts relevant to a particular interest can be found easily. Of course I am of an age that believes in the serendipity of browsing, so I’d recommend that also to anyone wanting to understand Bill’s ideas.” Matías adds “read the messages; without prejudices. The content of the messages will do the rest.”