BatMUD
You got hands?
BatMUD is a huge, fantasy oriented, text-based game that has been running since 14th april 1990. There are constantly over 100 players online with whom you can share the world, but if you prefer solitude, there is more than enough room for lonely wolf(man)s too.
New players might feel intimitated about the overwhelming freedom, amount of choices and the lack of walktroughs to a game where knowledge is power, help is always close in form of various help files, appointed newbie helpers and ever present administration. While there are mages, tanks, healers, hybrids, merchants and such rough generalizations running around you, they also represent races such as humans, gnolls, barsoomians, sprites, leeches, catfolk, demons, trolls, even couple moomins can be seen, vampires and such from the total of 44 different known races. They also represent their guilds, such as rangers, mages, templars, sabres, beastmasters, bards, reavers, assasins, merchants and so on from the 44 different guilds that are recruiting new members.
While in other games you might become frustrated if you made some bad choices when you started playing, in BatMUD there is no such worry. You can start playing without reading any guides how to make the best tank or dps maker or need of deep analys of different equipment combos as you can reincarnate your character to a new race, background and guild combination with relatively low tax on your total experience points. This enables you to reinvent your character without losing most of your gained power level. Players constantly sell equipment and sometimes even whole equipment sets so switching to mage after playing ages a barbarian, it only requires some selling and buying or plain trade, spell casted by a druid or a priest and you are ready to cast lava storms.
It doesn't matter if you are a socialiser, achiever, explorer or a killer, there are enough things to do for years and years to come. In the game you can join player societies (with related chat channels), for topics ranging from motorbike fans and food to computer hardware, etc. Many guilds are dedicated to making most of BatMUD, you name it and there is likely a society for it. For the questers among you, over 100 quests (none of which are compulsory for level advancement, apart from very few) that will keep you busy for years as you need to figure them out yourself while numerous awards are waiting to be claimed. General and guild-related plaques of fame and fortune showing players who have done most damage, most exp, most quests, most exploring, most powerful items, most top kills are often available for comparing your virtual provess to others. And there exist other fancy ways to boast what you have done and killed, too... NPCs that require hours and hours of hard effort to be slain are awaiting you.
The game can be played using plain telnet connection and dedicated MUD clients, but there is also a free, official Java-based client to play BatMUD, the [Batclient]. It offers maps, option to divide the information streams from different channels, triggers and macros, party info, just about anything you could ask for plus anything you might create yourself. Bandwith need for the game is minimal and lag is more or less an ingame joke.