At Anug last time we heard about F# and functional programming.
One of the things we discussed was polyglot programming:
Could one do a website where the UI was in ironRuby or ironPython, the business objects in C# and the harder calculations in F#?
Actually I brought this up, and nobody seemed to buy it. The reason people used was that you would have to be in a bigger enterprise in order to do this kind of polyglot programming, simply because it will be too hard to deal with all these different languages (Correct me if I got this wrong!).
But I would state that polyglot is already here, if you do a website on your own you deal with:
This is not a big problem, and one of the things that makes this possible is intellisense and google.
Intellisense makes it fluent to write the syntax and find the right method and so forth.
Google gives you the opportunity to find other peoples solution to your problem.
So I will still state that polyglot is usable, and in use.
The good thing about the ironRuby/Python, F# and C# polyglot soup is that the underlying platform is the same. So all you know about .Net from you C# (or VB.Net) work still applies to ironX and F#.