New York-born Tomlinson is best known for selecting the @ symbol to connect a username with the destination address email, making it a central part of the communications process. While working for Bolt Beranek and Newman, the company that developed the first program for sending network email, Tomlinson chose the symbol — which was fairly obscure at the time — to differentiate local and global emails on a list. From there, it became the designation for address formats, which exploded as email went global as a communications medium.
In a 2012 interview with Wired, Tomlinson explained his choice:
“I looked at the keyboard, and I thought: ‘What can I choose here that won’t be confused with a username?’” Tomlinson remembers. “If every person had an ‘@’ sign in their name, it wouldn’t work too well. But they didn’t. They did use commas and slashes and brackets. Of the remaining three or four characters, the ‘@’ sign made the most sense. It denoted where the user was … at. Excuse my English.”
Tomlinson’s invention has had a larger modern-day impact too, shaping social media services like Twitter and Facebook, where @ is universally synonymous with direct communication with an individual.
In a biography, the Internet Hall Of Fame praised the impact of Tomlinson’s work:
Tomlinson’s email program brought about a complete revolution, fundamentally changing the way people communicate, including the way businesses, from huge corporations to tiny mom-and-pop shops, operate and the way millions of people shop, bank, and keep in touch with friends and family, whether they are across town or across oceans. Today, tens of millions of email-enabled devices are in use every day. Email remains the most popular application, with over a billion and a half users spanning the globe and communicating across the traditional barriers of time and space.
Fellow Internet pioneer Vint Cerf and Google’s Gmail team were among the many to pay tribute to Tomlinson.
Here’s Tomlinson’s induction to the Internet Hall Of Fame in 2012: