A few weeks before Musk sealed the $44 billion deal to take over Twitter, he said that acquiring it would be the first step toward X, "the everything app."
Musk has previously teased X.com as a possible Twitter competitor. In August, Musk responded to a question asking if he'd launch his own site instead of buying Twitter by tweeting "X.com."
X.com was originally an online bank co-founded by Musk in 1999. The company later merged with another online payment system and became PayPal. In 2017, Musk bought the domain name and relaunched the site.
At the time, Musk claimed he had no plans for the site but the domain had "great sentimental value" for him. Currently, the website displays a small x if launched.