To the two or three fans of Classic, the server has moved to ClassiCube

[masteronion 0]

-> ClassiCube.net <-

You'll need to create an account on ClassiCube to join the Classic server.

From the account page, you can download the standalone client (which will allow you to join both Minecraft.net and ClassiCube.net servers) and upload a player skin. It's all very well optimized so you shouldn't have an issue with any versions of Java.

ClassiCube's server list is available at
http://www.classicube.net/server/list/

and the Classic server is available at
http://www.classicube.net/server/play/84ce710714eedcdfd7ef22d4776671b0