Minecraft Snapshot 14w03a has been released!
Notable additions for mapmakers:
To get snapshots, open your launcher and press the “New Profile” button. Call it “snapshots” and check the box saying “Enable experimental development snapshots” and save. To switch to the normal version, you can select it in the dropdown at the bottom left corner of the launcher.
Cross-platform server jar: https://s3.amazonaws.com/Minecraft.Download/versions/14w03a/minecraft_server.14w03a.jar
Credits: The Minecraft and Minecraft Realms teams