How about anything that isn't developed solely for iPhone/iPad? Objective-C is high on the list because it's trendy to write iPhone apps, so people blog about

How about anything that isn't developed solely for iPhone/iPad? Objective-C is high on the list because it's trendy to write iPhone apps, so people blog about it and write a million "How to get started with objective-C" tutorials for it. Outside of that niche, and a really small group of OSX developers, there's zero Objective-C development. It's barely even possible to write Objective-C on Windows or Linux.