F# has very slick interop. It has first class support for .Net objects, so nearly all C# libs work fine from F#. There are a few exceptions, where library write

F# has very slick interop. It has first class support for .Net objects, so nearly all C# libs work fine from F#. There are a few exceptions, where library writers take really moronic shortcuts to make up for C# lack of basic features, like tuples and list literals. But that just makes them sightly silly to use, that's all. That's probably less than 5-10% of libraries. F# contains some sugar to gloss over a lot of ugly C# idioms so things generally work surprisingly smoothly. What I find more confusing is C#'s love of mutation. For instance, "fluent" interfaces, where you call an object's method and it returns the same object. I find it confusing in C#, and it seems even more out of place in F#. F# feels less complex than C# - less "axioms". I've not evaluated this even remotely formally, but it's the feeling I have, being familiar with both. F# really is faster and easier to work with. While yes, F# can't eliminate null references (even inside the language, you can force null) it is far less of an issue. F# has some of its own libraries, and then also you'll find wrapper libraries to F#-ise other libs. The F# community seems very helpful and excellent. Even the F# team is far more engaged than C#'s ever was. I'm so impressed that once I emailed them with an issue, and Don Syme offered to get me a custom build to tide me over until my problem was officially fixed. This was well after F# has started gaining stream. They are very nice people, and amazingly competent.