OpenGL is not a programming language; it is an API. You can access it with Xcode (free from Apple).
As for the poll, I use Objective-C and REALbasic, which fall under "other", and AppleScript. I occasionally use Perl, and I've done some small things with JavaScript, but I'm not very good with either of them. And I'm perfectly capable when it comes to HTML, but I don't consider it a programming language to begin with,