Inviso | platform tool for designing interactive virtual soundscapes | Runtime Evironment library

If you're thinking of expressing truly generic folds over arbitrary container types, a'la recursion schemes, directly within the F# (or CLR for that matter) type system - you're out of luck. Too much of the required machinery is missing in the language - most crucially higher kinded types.

HKT's can however be encoded in F# using a technique called defunctionalization. There is an F# library based on the concepts from this paper - Higher. In fact, it already implements fix, cata/ana/hylomorphisms and algebras as proofs of concept. I don't have a good gauge of how well that works though, both in terms of performance and ease of use.

Other than that, you can implement folds specialized for your containers by hand, obviating the need for HKT's. There's a classic by now series of blog posts on implementing catamorphisms here. It's well worth reading - beside folds it also goes in-depth into programming in continuation-passing style.