This is a neat idea, but I found it painful to use for anything but trivial examples, since the main thread pauses for a second or two every time I edit my code. (Using Chrome.)

I tried running this snippet: http://www.fssnip.net/7VB/title/Enumerating-the-Rationals

Problems I ran into:

* BigInteger isn't available, even though it's part of F# core and I opened System.Numerics.

* Syntax coloring failed when I defined static member (* ). It seemed to think that (* opened a comment that was never closed. (Sorry, HN formatting prevents me from typing the correct inline multiplication override.)