I want to make a lobby server in Bukkit and I need a plugin for it that adds the command
/server <server> I've seen many servers have this command. Does anybody know what this plugin is and if it's still available for download?
Take a look at BungeeCord
For a long time, Minecraft server owners have had a dream; a dream of a free, easy and reliable way to connect multiple servers together. BungeeCord is the answer to this dream. Whether you are a small server wishing to string multiple game modes together, an established 250 player server wishing to expand your capacity, or the megalithic monolith of the ShotBow Network, BungeeCord is ideal for you.
As stated above, BungeeCord (simply referred to as Bungee) is your absolute answer. Note that Bungee is NOT A bucket plugin, it is a proxy server that runs along side multiple minecraft servers. It uses a very small amount of system resources, and is fairly easily configured.
You may wish to use other proper plugins that can create portals that link to other servers for player's easy transport, as well as create a layer of transparency for your server network. Note that using bungee along side of some administration plugins like BanManager and the like will require some additional configuration, and thought into it's usage. As with default settings an IP Ban will ban everyone from your server, and possibly your network.