What's there to do 'differently' about a chat client? They haven't changed in the last 30 years or so. "Special features" could still be implemented by non-stan

What's there to do 'differently' about a chat client? They haven't changed in the last 30 years or so. "Special features" could still be implemented by non-standard protocol extensions while still being able to exchange bare bones messages with all clients which accept the standard protocol.