Once upon a time, a long time ago, 16 bit color was considered advanced graphics. In this strange and distant time, bandwidth was measured in bytes and "mega" was reserved for physical storage. It was a digital world almost, but not quite, completely unlike what we see today. And yet, like a dinosaur that just won't go extinct, something from this far distant past is still with us right now. Not only with us, this ancient relic has a powerful effect on the gaming landscape today.
The living heirloom? Muds. Multi-User Dungeons are the early predecessor to the modern MMOs. And yes, many of them are still around with regular players and active communities. Muds are intimidating to the modern gamer, and that may be unfortunate. Every modern RPG has within it the soul of a Mud. Strip away the impressive visuals and the user interface, and you are left with something that would be right at home in decades past.
The play experience of a Mud, like any modern MMO, largely depends on the control scheme. Like any modern game, the player operates within the game world by means of commands. In a modern game, those commands are largely entered with the mouse or keyboard hot-keys. In a Mud, those commands are typed. This isn't as bad as it sounds at first. Once you master a basic command vocabulary, and the world is pretty much yours.
Why bother? Why not just stick with modern MMOs? Two main reasons, I think. First, nostalgia. Rather than spending thousands on a restored '57 Chevy, you might reconnect with the past by spending a few months online in an old school Mud. But beyond the quasi-emotional allure of yesteryear, consider the low barrier to entry for both developer and gamer.
For developers, the Mud might be the easiest multiplayer game to make. So long as there is a good fictional world to explore and some good stories to tell, the Mud can be born. No need for artists or advanced particle modeling or complex UI designs. Muds, then, are ideally suited to the needs of hobby game designer or closet story teller. For the gamer, there is no such thing as computer that cannot run a Mud. Even netbooks can get you into the game if the operating system in question can manage a Mud client. And with many Mud clients being Java-based, even that is not much of a problem. With a Mud, online gaming can hit the road in a way modern MMOs just can't.
Getting started is surprisingly user friendly as well. There are websites out there dedicated to the Muds among us and to getting new Mud-ers into the game. Mudconnect is one such place. When picking a Mud today, I would suggest you make a stable community one of your highest priorities. After all, like any MMO, a Mud is as much about its people as anything.