Regnum Online is a free to play MMORPG that is developed in Argentina for Windows and also has an unofficial Linux client. It is somewhat similar to Guild Wars (which unfortunately does not work under Linux). Check it out, as it is one of the best free MMORPGs I have played.
The world is divided into three separate realms (kingdoms) that are at war with each other. The game has both PvE and PvP, many quests, and impressive 3D graphics that are on par with many other commercial MMORPGs. You can choose to be a Human, Elf, Dark Elf, Half-Elf, Morlock, or Utghar. You can be a Warrior, Mage, or Archer, and each one has two subclasses that become available in later levels - Knight, Barbarian, Warlock, Conjurer, Marksman, or Hunter. The game does have a slight commercial side to it as they sell premium content, such as renting horse health and mana regeneration potions, and an experience boosting scroll.
