Polyglot programming - combining functional, dynamic and imperative languages

I've always liked the idea of polyglot programming. How much better would it be to not have to try & kludge programming paradigms out of languages that don't support them, but could just use a language that does what you want natively.

The problem, as the author found is the boundaries between the languages & having them all play well together. It's not hard to get related languages to work together but it's great to learn more about getting disparate languages to interact in a working program. The idea just seems cool.

One thing I don't get: how does someone keep up with the news of that many different languages such that they know what the best libraries are for achieving x in five different languages?

Wow. These guys are legends.