The Altar is a custom Pokemon-Planet feature and is located in Vermillion City.
When the target of $4,000,000 is reached, double experience will be applied to the entire server for 1 hour. To check if the Altar is in use, look in the top-left corner.
Money or Credits can be donated to reach the target. You can check how much money has been donated by typing /altar in chat.
Donating 1 credit converts to $2,000
For every $800 donated, you will receive 1 Philanthropist Point (rounded down).