An SMS experiment became the world's newswire, then a billionaire's obsession. On its 20th birthday, Twitter's legacy is complicated. From an SMS-inspired platform to the world's real-time information infrastructure, Twitter – now X – evolved from a microblogging experiment into a digital town square over two decades.Twitter, now X, began as an SMS-inspired platform. (Featured image: HT)A star is bornTwitter, originally called twttr, launched on July 15, 2006. Months earlier, co-founder Jack Dorsey posted the first tweet: “just setting up my twttr.” It took off at the 2007 SXSW conference, when real-time updates made it an instant hit.Changing the online lexiconTwitter soared after user Chris Messina proposed using the "hashtag" (#) in 2007 to group posts. The retweet soon followed, reshaping how information spread online.The world's newswireIt became a real-time news platform in 2009 when a passenger posted a photo of US Airways Flight 1549 after its Hudson River landing. During the Arab Spring in 2011, protesters used it to organise demonstrations and bypass state media.Also read: 15-day govt notice for Telegram to act on piracy channelsChange in structureEvan Williams replaced Dorsey as CEO in 2008; Dick Costolo took over in 2010; Dorsey returned in 2015. Twitter also introduced an algorithmic timeline and expanded posts from 140 to 280 characters in 2017.Vine and brain rotTwitter bought Vine in 2012. Though it shut down in 2017, the six-second video app helped shape today's short-form video culture.Also read: Govt extends deadline for WhatsApp to respond to username issue to July 9HT GraphicThe Musk eraMusk bought Twitter for $44 billion in 2022. Verification became paid, moderation changed, and Twitter became X in 2023. In 2025, xAI acquired X in a deal valuing it at $33 billion.Vishal Mathur is Technology Editor for Hindustan Times. When not making sense of technology, he often searches for an elusive analog space in a digital world.See Less