As an exercise my team is looking at learning functional programming. One of the factors to choose a language is its support in Eclipse. Any language with Eclipse plug-in is fine but what language offers the best free plug-in?
Bonus question: the best online/book tutorial for this language.
I don’t know if it is the best, but it is evolving and improving fast:
Scala IDE (up to Scala2.8.1RC1 right now)
As for the best online Scala book:
Programming Scala (Creative Commons Attribution-Noncommercial)
But you will find other online sources in the SO question “List of freely available programming books“.