Flint is a software toolkit which supports various modes of uncertainty handling, namely, Fuzzy, Bayesian and Certainty Theory.
Along with Flex, Flint was licensed to the Open University as part of T396: 'Artificial intelligence for technology'.
Much of the material for this course is described by Prof Adrian Hopgood in his book: Intelligent Systems for Engineers and Scientists, Third Edition, and on his web-site.
Flint is produced by LPA and runs on PCs and web servers.
References
Flint toolkit Wikipedia(Text) CC BY-SA