Perlmoo is a server for a virtual world, a computer program which users can log into and explore. Each user takes control of a computerized persona / avatar / incarnation / character. You can walk around, chat with other people, solve puzzles, and even create your very own rooms, descriptions and items.

Perlmoo is intentionally similar to lambdamoo from the user's perspective, but it's written as object oriented perl code, that can easily be modified and expanded. It's possible to code new object in perl while the moo is running.

Perlmoo has been supersceded by its successor, mooix. Check out mooix's website for details about mooix.