OOP on Linux: Best languages.

I've never programmed in Linux before and I suck without an IDE. What is a good IDE and good language to use for OOP on Linux. I've been learning C# recently and wanted to stick with it. Is there a good IDE that uses Mono natively?

I raged at this thread.
OOP IS SO 1990'S.
_{Go the fuck away from GNU/Linux back to your windows enterprise pile of best-practices dead horse poo.}