An NFT representing the source code for the Internet as we know it were sold at auction Wednesday evening as a nonfungible token, or NFT, for $5.4 million, becoming the latest digital collectible to fetch a multi-million dollar price. 

The NFT, called “This Changed Everything,” was sold in a Sotheby’s auction by Sir Tim Berners-Lee, who invented the World Wide Web application in 1989.

In addition to the nearly 10,000 lines of code that made up the backbone of the internet, the NFT also includes a recent personal letter by the computer scientist reflecting on his process, as well as an animated video and digital poster representing the code. 

The code includes languages and protocols such as “HTML” and “HTTP,” that allow sites to be displayed in a web browser.

The winning bidder remains unknown. 

The proceeds from the sale will go toward charities that Berners-Lee and his wife support, Sotheby’s said.

“While the source code to the web itself is a digital artefact that has existed since 1990, it is not until the emergence of NFTs that something like this could ever have been harnessed for sale,” Oliver Barker, Chairman of Sotheby’s Europe, said in a statement.

Berners-Lee defended the sale from critics who may claim that selling a multimillion-dollar NFT does not align with the original “free and open” spirit of the internet in an interview last week with the Guardian. 

“The questions I’ve got, they said: ‘Oh, that doesn’t sound like the free and open web,’” said Berners-Lee. “Well, wait a minute, the web is just as free and just as open as it always was, the core codes and protocols on the web are royalty free, just as they always have been. I’m not selling the web – you won’t have to start paying money to follow links.” 

“I’m not even selling the source code,” he added. “I’m selling a picture that I made, with a Python program that I wrote myself, of what the source code would look like if it was stuck on the wall and signed by me.” 

NFTs are digital assets that represent ownership of virtual items — such as a video clip of Lebron James dunking a basketball — and act as a certificate of authenticity. Ownership of NFTs are recorded on a blockchain network, which supports cryptocurrencies such as bitcoin and ether.

The pieces of digital art have fetched eye-popping prices at auctions this year. The movement has caught so much attention that major, centuries-old auction houses like Sotheby’s and Christie’s have now sold NFTs.

While the market for NFTs appears to have dropped off since it peaked earlier this year, the latest sale at Sotheby’s shows that the market remains strong.