Garrett Murray didn’t invent the Twitter @-reply, but he provides some good background on its history:
I have always half-jokingly taken credit for inventing the @reply on Twitter. Or at least for starting its wide-spread use on Twitter—I got the idea from seeing people do it over at Flickr, where it had been happening for more than a year. But until today I continued to claim I was the first person to do it on Twitter. Recently, user @rabble put together a blog post titled Origin of the @reply – Digging Through Twitter’s History, in which he did some research to show when it was first used. Only his research isn’t entirely correct and it doesn’t give fair credit to everyone involved.
It turns out that I’m not the inventor of the @reply, though I’m definitely one of the pioneers. Robert Andersen seems to be the father of the @reply on Twitter. He sent this message on November 2, 2006 at 8:58PM (all times in this post are Pacific—if you’re reading this from the Tumblr Dashboard, all the dates will look funky):
@ buzz – you broke your thumb and youre still twittering? that’s some serious devotion
I like his thought about collective consciousness when he and a bunch of other people started using the (now indispensable) @-reply on the same day in November 2006.
Related: the Twitter hashtag (#) was invented by Chris Messina in 2007.