Webzen, the answer is "throw a party in every game we have." Webzen is celebrating its first anniversary with special updates and events in MU Online, Archlord, and Soul of the Ultimate Nation.
MU Online players will find new content with the game's second major update. New maps, new items and more are being added to the game as well as giveaways of jewels and ZEN. The NPC Leo also has some special gifts for anyone purchasing gold channel tickets before the 18th.
Archlord is celebrating by inviting more people to the party, so to speak. Webzen is adding an American server to the game, and invites players in North and South America to join the fun.
Finally, Soul of the Ultimate Nation wins the prize for the flashiest celebration with the week-long Mayan festival. The event is going on now, with huge XP bonuses for returning players, special items in the shops, and a "matching" program when you purchase W Coins. Check out the event page for all the details, and congratulations to Webzen!