Ubuntu is a free, open-source Linux operating system developed by Canonical and first released in 2004, widely used on desktops, servers and by developers. Its startup sound became a familiar cue for Linux users opening their computers, and over time it spread beyond the desktop through soundboards, tech videos and memes about switching from other operating systems. It remains popular because it is short, instantly recognisable to tech audiences and carries a nostalgic link to early open-source computing.