From Markus Persson:
Minecraft Server is a game about placing blocks to build anything you can imagine. At night monsters come out, make sure to build a shelter before that happens. It also has music by C418. Play against online opponents and score points with this game. It allows players to play online with other people. They may either be run on a hosted Minecraft server service, a dedicated server, a Virtual Private Server or a home machine. This is not a list of servers.
What's new in this version:
Version 1.5.2 includes performance improvements when using HD texture packs.