Ultima Online Windows, Linux game

Is a enter the magical world of Ultima Online, create your own adventure MMO in high medieval fantasy, A world with spells, monsters, quests and heroes. A living, growing world where thousands of real people discover fantasy and adventure 24 hours a day, every day of the year.

It is known for its timing-based player versus player combat system, unique character classes (animal tamer, a mage, a warrior, a blacksmith, carpenter, tailor, or even a ninja) near perfect balance, player run guilds, towns and cities, and its community oriented character progression.
Ultima Online requires a modest monthly fee which runs across multiple game servers known as shards. Multiple expansions have been released since Ultima Online’s launch but, its game engine and graphics make it outdated compared to recent massively multiplayer games. This however changed in 2007 with the release of Ultima Online: Kingdom Reborn which features a new game engine with updated graphics.

Ultima Online is one of those rare games that never die, continually sells to this day, while graphically it may not be much compared to its modern day RPG MMO's brothers, It has a special magic that only a handful of MMOs have captured (let alone topped) since, and what it lacks in modern conveniences it often makes up for in unique features. Boasting 135'000 active online players, accounts for %0.6 of the MMO world playerbase, getting free content updates for many years to come (latest expansions was Stygian Abyss in 2009, and new booster packs in 2010).
A new expansion is coming in 2014, titled Ultima Online Virtue & Valor.