In reading through Steve Yegge's old blog, I found a statement that perfectly summarises what selecting a programming language for a complex project is like:

So... the best way to compare programming languages is by analogy to cars. Lisp is a whole family of languages, and can be broken down approximately as follows:

• Scheme is an exotic sports car. Fast. Manual transmission. No radio.
• Emacs Lisp is a 1984 Subaru GL 4WD: "the car that's always in front of you."
• Common Lisp is Howl's Moving Castle.

This succinct yet completely accurate synopsis shows that all Lisps have their attractions, and yet each also has a niche. You can choose a Lisp for the busy person, a Lisp for someone without much time, or a Lisp for the dedicated hobbyist, and you'll find that no matter which one you choose, it's missing the library you need.

Except replace the lisp dialects with every language ever written, and factor in portability issues, and you now know what it's like to be a multi-lingual programmer xD.