Six years ago today, the first ever tweet was sent by Twitter co-founder Jack Dorsey. And today, there are over 500 million registered users sending more than a billion tweets a week. You’ve come a long way, baby!

The tweet below contains the first, fateful words ever typed into Twitter. Dorsey was with fellow co-founders Biz Stone and Evan Williams tweeting to each other and a small group of family friends during those first few weeks, getting the service up and running.

just setting up my twttr

— Jack Dorsey (@jack) March 21, 2006

Six years ago, Twitter (which was known as Twttr back then) was meant to be a mobile phone-based service, which is why each tweet is only 140 characters, plus 20 characters for the username of the sender – 160 is the length of a SMS or text message.

A year after its creation, Twitter went on to win in the “Blog” category at SXSW, and Dorsey famously thanked them in a tweet.

Since then, Twitter has achieved mainstream success, becoming an integral part of TV newsrooms across the US, facilitating communication during political uprisings in the Middle East, and acting as a message board for celebrities and their fans to communicate through.

It’s also grown as a company, going from no revenue for the first four and a half years to being one of the social media ad platforms of choice for big brands like Coca-Cola, McDonalds and Audi. And although the question on many people’s minds is when Twitter will go public, the 140-character social darling is content to just celebrate its 6th birthday just like it’s last birthday!

So happy birthday Twitter, and here’s to many more to come!

(Birthday image via Shutterstock)