FSharper is an implementation of F# for ReSharper. It targets ReSharper 6.

Requirements

What you need is:

• VS2010
• ReSharper 6 SDK (soon to be released)
• ReSharper 6 for testing

Challenges

• F# is not fast enough in order to parse/lex F#. Sorry but it's true. Alternatives such as C++/CLI are being considered.
• Managed languages might not be the best idea to deal with F# in terms of performance. This concerns mainly issues regarding type inferencing.
• F# has an impedance mismatch with ReSharper. R# is basically all-OOP whereas F# isn't good at this, which results in all sorts of weirdness, such as returning Unchecked.defaultof<> values. We still need to connect the two at some point,

Opportunities

• F# is by itself pretty good once you get object models in place. For example, pattern matching is very relevant while analyzing code.
• F# project files always appear in order, which offers a potential performance advantage in terms of multithreaded parsing.
• It might be possible to take lexing and parsing off the CPU, letting it do some other R#-related work instead.