What program was Minecraft made in?

When I say this, I don't mean "what coding language was it made in", no, I mean what program, I know it's made using Java.

Added (1). Also, it would be nice if you could respond with a download link for the program

In 2011, Notch partook in Ludum Dare #21. He used Eclipse to write the game.
http://www.mrspeaker.net/2011/09/15/code-like-youre-notch/

Netbeans is also nice, and so is IntelliJ IDEA. It doesn't really matter anyway, as long as you use a proper IDE (with all the stuff that makes coding less annoying).

http://www.eclipse.org/downloads/