The Wikimedia Foundation is a collection of many innovative and revolutionary wiki-projects. Each project is free and open for anyone to edit. Anyone and everyone is invited to donate time, knowledge and finances to the furtherance of the projects. These projects are a world community effort, so your knowledge of a subject and taking the time to contribute to the content of the site is invaluable. And of course, the up keep and maintenance of the projects cost money so your finances are invaluable as well.