LEGO Universe: Official site of the MMO that focuses on building, battles, and racing. Information about gameplay, the game world, events and contests, parent's guide, forums, and account management

Minecraft: Official site of the indie building game. Includes forums, FAQ, browser-based play, single player and multiplayer versions and server downloads for Windows, Mac, and Linux

ROBLOX: Official site of the free MMO building game for kids. News, contests, forums, parent's section, and merchandise