Publisher: Hozer Video Games

Hozer Video Games is the name the site lists for Sound X, a cartridge by the hobbyist programmer Ed Federmeyer. Sound X is not a game but a tool for exploring the noises the 2600’s sound chip can make. Federmeyer wrote it in the mid-1990s, after Atari had stopped selling the console, and shared it with other fans on Usenet. It is one of the earliest 2600 homebrews, and his use of the word “homebrew” for this kind of hobby work stuck. Several builds exist, dated 1994 and 1996.
You can experiment with it below in your browser.