Going back seven years, the first tweet to direct a tweet at someone was Robert Anderson to Buzz Anderson (no relation)

@ buzz – you broke your thumb and youre still twittering? that’s some serious devotion

— Robert Andersen (@rsa) November 3, 2006

(Also, note the verb “twittering” – how times change)

This wasn’t a recognised standard though – it was only when Ben Darlow suggested a pseudo-text standard that would inform a user of a tweet directed at them.

wondering if there should be a pseudo-syntax for letting a Follower on twitter know you’re directing a comment at them.

— Ben Darlow (@kapowaz) November 23, 2006

Neil Crosby was quick to respond in an appropriate manner:

@kapowaz: probably

— Neil Crosby (@NeilCrosby) November 23, 2006

Thus, the @reply was born.

It wasn’t until May 2008 – 18 months after the suggestion – that it was officially supported within the application although there was unofficial support through third party tools and services beforehand.