Battle.net announces that alpha testing is now underway for the upcoming Warlords of Draenor expansion for World of Warcraft, Blizzard's MMORPG. They offer a technical discussion of a new proprietary file format they are introducing, outline how to sign up to be a beta tester, and remind users how to keep their accounts more secure. Here's what they say about testing the new addon:

We’ve been hard at work on World of Warcraft®: Warlords of Draenor™, and today we’ve entered the Alpha phase of our expansion testing. As part of this, we’ll begin using public servers to host the data, which means you may begin seeing some datamined information show up in the usual places.

One of our goals for this very early stage of the Alpha is to test out some new technology in the wild with employees and friends and family, including a new file format called CASC (more on that below). As such, the expansion content available during this first phase will be quite limited—many of the expansion’s major features, such as Garrisons, won’t be available until a later point in the testing process. This early phase of testing will help us ramp up for our larger beta phase later on, when we’ll be inviting more players.