But basically there's a bit of data you put into your MOTD to get World of Minecraft client to load a file from your webserver.

This data you put in is like:

"cfg=server.com/config.txt"

The config.txt file at http://server.com/config.txt will spit out client configuration information as per the document at http://files.worldofminecraft.com/textures.php

If you want the client to tell your server that it is a World of Minecraft client and can support extra data to be displayed at the top right, put in the "server.sendwomid = true" field.

When the client connects to your server it will send a command like "/womid 1.8.8" upon seeing this message your server can then send detail messages to the client to manipulate the data in the top right area.

Now in the World of Minecraft client, the top right fields are:

server.name
server.detail
detail.user
announcement1
announcement2
...
...

The server.name is the name of the server specified as server.name in the config.txt or the name supplied by the server to the client when it connected if not in the config.txt.

The server.detail is the server.detail line in the config.txt file.

The detail.user field is in the detail.user line in the config.txt file, and can be overridden by the server sending a detail message to the client.

The announcement fields are also manipulated by sending detail messages to the client.

A detail message looks like this:

^detail.user=Hello world.

This particular message if sent to a World of Minecraft Game Client, will change the third line to "Hello world."

The following detail messages are currently supported.

detail.user - Set the third line message.
detail.user.reset - Clear internal user list.
detail.user.here - Tell the client the user is here already.
detail.user.join - Tell the client the user has just joined. (This will announce the join in the announcements area)
detail.user.part - Tell the client the user has just left. (This will announce the departure in the announcements area)
detail.user.alert - A freeform announcement to add the the announcements area.

Here is an example typical session:

Client connects to server.

Authentication occurs.

Server sends Server Identification packet to client with Server name field set to "++++ My Server ++++" and Server MOTD field set to "Welcome +hax cfg=tinyurl.com/af47djk"

Client downloads http://tinyurl.com/af47djk which is a config file that tells it:

server.name = My server.
server.detail = Welcome to my server!
detail.user = Greetings user.
server.sendwomid = true

Upon downloading this, the second line in the connecting screen will change to "Welcome to my server!".

As soon as the map loads, the top right area of the screen will now say:

My Server.
Welcome to my server!
Greetings user.

The client will then send a command to the server: "/womid 1.8.8"

The server can now store the fact that the World of Minecraft client version is 1.8.8 and can accept detail messages.

The server then sends some messages to the client like:

^detail.user=Hi there triddin.
^detail.user.here=spreckle
^detail.user.here=H4X
^detail.user.alert=Please don't grief my server
^detail.user.join=Artful
^detail.user.part=H4X

The top right part of the screen will now read:

My Server.
Welcome to my server!
Hi there triddin.
Please don't grief my server
Artful has joined
H4X has left