Asciiquarium
Enjoy the mysteries of the sea from the safety of your own terminal
...The project is written in Perl and designed to run in Unix-like environments, making it simple to install and execute on most systems. While not intended as a practical tool, asciiquarium has become a popular example of creative programming in the terminal, often used for fun or as a screensaver-style distraction. The animation is randomized, so each run produces a slightly different underwater scene. As an open source project, it has been adapted and extended by the community over time, ensuring compatibility and continued enjoyment for terminal enthusiasts.