The First Photo Ever Uploaded to the Web
So when Berners-Lee and his team cooked up a new edition of their still-primitive World Wide Web system, one that could support photo files, he went a few steps from his workstation to ask de Gennaro for a Cernettes-related image. The Web had already used a few small vector image files to show off schematics, but Berners-Lee and his team needed a guinea pig for the leap into photos.
Lucky for him, de Gennaro had been toying around with a scanned .gif version of the July 18th photo, using version one of Photoshop on his color Macintosh. The .gif format was only five years old at the time, but its efficient compression had made it the best way to edit color images without slowing PCs to a crawl.
Found via Petapixel.