I actually have a few expert systems in production, but you'd have to have to be really into GOFAI to recognize them as such. I pointedly didn't tell my bosses I was solving those problems with AI, because if you tell people you're doing AI they assume you're doing something overly ambitious and say 'no'. I bet there are a lot of those out there.
Yeah! Open source is great and all, but so much code exists inside organisations and there's no telling what kinds of methods they're using. I have a friend at Google who mentioned offhand that employees can sift through billions of lines of internal code. I wonder how much internal software itch-scratching has found totally novel methods of solving problems. I'm not sure if it's really possible to know.