From Minecraft Wiki
August 11, 2010
Alpha 1.0.16 added new features and commands for servers.
- Added online authentication for online servers
- The server can now be started in either online/secure mode or offline/insecure mode. A secure server requires all connecting players to first authenticate on www.minecraft.net, then checks that the authentication matches, before letting the player in. A server running in offline mode won’t do any such checks, nor will it ask the client to authenticate, but you can’t be sure that people who connect really are who they claim they are. Offline mode is meant for LAN plan where you know the people connecting to the server.
- Server commands
- Added ban/pardon commands to ban and unban a player from the game
- Added ban-ip/pardon-ip commands to ban and unban a specific ip (you have to kick the player manually)
- Added op/deop commands to add/remove a player from the op list
- Added player ops. They can send server commands by typing a slash followed by a server command. Server ops can also build/destroy blocks near the spawn area.
- Support for more records
- Made the server save terrain more frequently