Stand alone client

The Minecraft stand alone client is a downloadable offline client that was released on June 30th 2010 for Windows, MacOS X and other systems that support Java such as Linux. It currently only runs Beta but is able to connect to survival multiplayer servers as well. Client mods only work with the stand alone client as they directly modify minecraft.jar, the executable of Minecraft. Before beta 1.3, a new version of the client was released with new features including a changelog and links to Mojang staff twitter accounts.

The client accepts command line arguments to automatically login and optionally join a server. Format: Minecraft username password server:port

Download
The stand alone client only requires an internet connection for the first time run and for automatic updates. After that the game can be played offline with ease.
 * Windows, MacOS X, and Linux downloads