Wikipedia is a multilingual, web-based, free-content encyclopedia project that was launched in 2001. It allows users to collaboratively write and edit its articles, making it one of the largest reference websites, attracting over 200 million visitors monthly. Wikipedia operates on a wiki model, is non-profit, and is funded primarily through small donations from its users. It provides the benefit of free access to the sum of human knowledge and allows for ongoing community improvements to content.