That's why I also said Ruby.
But normally these files in the Xcode navigator are just white. But the odd time I will see this icon with "rb" in the Navigator. There's no extension of a pod file n my finder. It's just a black icon with the name pod file.
It's like a small number of people are creating their pod files with a different editor than most people.
For example I just use Xcode -> New File. Those people are creating them from cli?