That was Netscape's story at the time when they were being sued for copyright infringement, but it was fairly obvious that there was a certain amount of code copying. There were error messages with the same misspellings in them... Anyhow Netscape decided to settle the lawsuit and give UI the Netscape stock. Interestingly UI then licensed Mosaic to a company called Spyglass, and that version went on to become Internet Explorer 1.0.