Java Edition Indev

Indev is the latest test version of Minecraft's Survival mode and contains features that are not yet implemented in the public version of Survival. It has proved in the past to contain bugs and ranges in stability from build to build.

You must buy the game in order to play indev.

Features

 * Map generation screen with configurable Map Themes, Map Types, and Map Shapes.
 * 6 Mobs; Zombies (drop Feathers), Skeletons (drop Arrows), Creepers (drops Gunpowder), Pig (drops Pork), the Spiders (drop String), and Sheep (always drops Cloth on first attack).
 * Using a Bow, the player can shoot Arrows.
 * The Block or item currently selected is visible, while the player's hand is visible by default.
 * Consume food to restore health.
 * Mushrooms by themselves have no effect. They can be combined with a bowl for Mushroom Soup.
 * Consuming Pork, Grilled Pork, Mushroom Soup or Bread also restores health.
 * A new tesselator to speed up the game.
 * Different map Themes.
 * F5 changes to a 3rd person view.
 * F7 captures isometric screenshot.
 * The player can drown in Water after fifteen seconds. Every second spent in Lava inflicts 5 Hearts of damage. The player will continue to burn afterward.
 * You can craft blocks of TNT. Placing and then meleeing them will cause them to explode after a short delay. Meleeing the block a second time stops the countdown and allows the block to be picked up.
 * Decorative Paintings.
 * Equipment and Weapons.
 * Farming.
 * Crafting.
 * Dynamic Lighting.
 * Exclusive Block types.
 * Updated Mobs (path-finding, varying difficulty options).
 * Day and night cycle (including a sun and moon).
 * Armor.
 * New map format (.mclevel).

Upcoming features
Notch's to-do list

InfDev replacing InDev
Indev has now been replaced by infdev, in the sense that indev no longer gets updated, infdev now get's most, if not all the updates. It is speculated that all original Indev maps will be able to be loaded into the new version.

For those who like InDev and don't like InfDev fear not. It has been confirmed that while InfDev will replace InDev as the main focus of Minecraft post-beta, smaller maps will still be available for those with less powerful computers or who just like the "less to worry about" atmosphere of current InDev style maps (reference)