Monopoly Online is a version of the game that can be accessed on the internet and that allows multiple players to play a variation of the classic Monopoly Board Game. There are various versions of the game available some of which allow customization of the rules and game play others offer board variations others even offer spin off games only loosely based on the original game system if at all.
There are web sites that offer totally free versions and others that offer only subscription or fee based options even some that offer a free version and also a fee based version or a purchase option that has enhancements or that will allow you to download the client for online play. http://videogames.lovetoknow.com/wiki/Play_Monopoly_Online
History of Monopoly
In 1903 a woman whose name was Elizabeth Maggie created a board game called The Landlords Game. She designed the game to be a learning tool to teach Henry George's single tax theory.She gained a patent in 1904 which expired in 1921. She made changes to the game and applied for a new patent which was granted in 1924. As time went on and the game grew i popularity various other folk patented their own sets of rules.
Then Charles Darrow acquired a set of rules, changed them slightly and had them copyrighted and began manufacturing copies that he called Monopoly. Parker Brothers acquired the game form Darrow and then found out when they went to patent it that he really didn't own the rights as the 1924 patent was still in effect. Parker Brothers then approached Mrs. Phillips nee Maggie and was able to obtain an agreement from her then they went after the many other small manufacturers of variations of the game. The game is now manufactured by Hasbro and has many different versions including online and down loadable computer versions. http://www.monopoly-history.com/
Monopoly Online Availability
There are many sites that offer Monopoly online in its various forms. Monopoly Here and Now World edition is offered on Pogo.com. EA.com also offers a spin off called Bank Pays you Dividends. There is a 3D version available but it must be downloaded but you can still use it to play online. IN 2209 a version from Hasbro called Monopoly city streets was released and greatly expanded the realm of play but sadly it closed down only 3 months after it was released. http://www.hasbro.com/monopoly/en_US/discover/news/Monopoly-City-Streets-Has-Ended.cfm