Wiki software (also known as a wiki engine or wiki application) is collaborative software that runs a wiki, i.e., a website that allows users to create and collaboratively edit web pages via a web browser. A wiki system is usually a web application that runs on one or more web servers. The content, including all current and previous revisions, is usually stored in either a file system or a database. Wiki software was invented and first created by programmer Ward Cunningham in 1995. There are currently dozens of actively maintained wiki engines, in a variety of programming languages, including both open source and proprietary applications. The first wiki application, WikiWikiWeb, was created by American computer programmer Ward Cunningham in 1994 and launched on c2.com in 1995.