What was the first killer app on the internet?

Answer 1

The first killer app was not really an app, it was the technology that allowed the internet to grow from a loosely related group of servers to a homogenous network.

To the user, it would have been the "@" mark.

Before the "@" mark, you had to know how to get an email to its recipient hop-by-hop. You had to know what major servers existed between you and them, and tell the mail client to send it via that path (Google "bang paths"). If a server went away, your email never reached its target.

After the @ mark, collarboration and communication became easier.

Hand in hand with that goes the DNS system, where easily remembered names substituted for the IP addresses that sometimes had to change.

Hurray for the killer AT!