If you know of any real world applications of category theory, please let me know. I would be interested to know of clearly described applications rather that anticipated ones using categories in background theories. When we speak about "applications of categories" or "applied categories" we mostly or almost exclusively mean applying categories within mathematics (or theoretical computer science), where we have categories in algebra, topology, logic (and type theory), and so on. We do have real world applications of algebra, topology, logic, and many other branches of mathematics, but possible use of categories is then hidden and/or indirect. Therefore the question: Are categories applicable in the real world? Application areas could be found within the public or private sectors. In the public sector it can be e.g. within education and health, and in the private sector in can be e.g. within energy, finance and manufacturing. If I receive more than just a few replies, I will make a survey of it, and later on inform the mailing list about the survey. Looking forward. Best, Patrik -- Prof. Patrik Eklund Ume?? University Department of Computing Science SE-90187 Ume?? Sweden ------------------------- mobile +46 70 586 4414 website www8.cs.umu.se/~peklund [For admin and other information see: http://www.mta.ca/~cat-dist/ ]