Nyan Cat is the name of a YouTube video uploaded in April 2011, which became an Internet meme. The video merged a Japanese pop song sung by Hatsune Miku with an animated cartoon cat with a Pop-Tart for a body, flying through space, and leaving a rainbow trail behind it. The video ranked at number 5 on the list of most viewed YouTube videos in 2011.

Source code (or a link to it) is included in the archive or on the production page. Note this doesn't necessarily mean the production is free software (FOSS).