Infdev (or infinite devlopment) was the third phase in the development cycle of Minecraft and is only playable in single-player Survival mode. Infdev no longer gets updated, and its link has been removed from the Minecraft website. Infdev, along with Indev, were still available on Minecraft.net up until September 2010, and to play Infdev now, players must use the option for playing another version of the game in the new launcher. Ever since Infdev, maps generated terrain theoretically 8 times the size of the Earth. The edge of the map limits the world to 64,000,000 blocks by 64,000,000 blocks, or 4.096 trillion square km. Infdev succeeded Indev when Notch decided to rewrite the game's code to allow terrain to be "infinite" and procedurally generated rather than finite.This principle of how maps are generated is similar to how current Minecraft levels are. Infdev was also the first appearance of the Far Lands. Because Infdev's main purpose was to catch an infinite terrain version up to par with Indev's content, that purpose was filled around June 2010.
Infdev was replaced by the name of Alpha as a sign of progression towards release.