The main difference is that this enables private messaging between users, regardless if they are signed up or not. Next time you're in a thread, you'll see a bu

The main difference is that this enables private messaging between users, regardless if they are signed up or not. Next time you're in a thread, you'll see a button to send a message next to their username. Click, and it will start a message without you having to leave the page. HNChat on the other hand seems to be more of a separate place to have conversations as a group. I feel like there is a place for both, they just solve different problems