Google Talk was federated and could chat with people who had accounts other Google, so it feels a bit unfair to lump that in. It's like saying "Gmail is compat

Google Talk was federated and could chat with people who had accounts other Google, so it feels a bit unfair to lump that in. It's like saying "Gmail is compatible with hypothetical Gmail where you can only send emails to other Gmail users, it's just a different iteration." Maybe true, but suddenly a very different service.