This is a category for Entropia Universe (formerly Project Entropia) which is a Massive Multiplayer Online Game / Virtual World consisting of the Entropia Universe platform and several game worlds in form of "planets". The Entropia Universe platform is being developed and managed by Swedish company MindArk while the planets are developed and managed by partner companies, so called "Planet Partners". In 2013 there are five planets available: Planet Calypso, ROCKtropia, Next Island, Planet Arkadia and Planet Cyrene. More are (or at least were) under development: Planet Toulan and Theryon Wars. Entropia Universe' distinct feature is the "Real Cash Economy": the ingame currency "Project Entropia Dollar" has a fixed exchange rate of 10:1 to the US Dollar, real-world money can be converted into game money as well as the other way round. Entropia Universe is free-to-download and partially also free-to-play and was released (respectively announced to be "Gold") on 30th of January, 2003. The sub-categories of this category contain links to websites primarily dealing with Entropia Universe, including official websites and community websites, and as well contain links to Entropia Universe related content on other websites not primarily focussed on Entropia Universe.