Wiki software (also known as a wiki engine or a wiki application), is collaborative software that runs a wiki, which allows the users to create and collaboratively edit pages or entries via a web browser. A wiki system is usually a web application that runs on one or more web servers. The content, including previous revisions, is usually stored in either a file system or a database. Wikis are a type of web content management system, and the most commonly supported off-the-shelf software that web hosting facilities offer. There are dozens of actively maintained wiki engines. They vary in the platforms they run on, the programming language they were developed in, whether they are open-source or proprietary, their support for natural language characters and conventions, and their assumptions about technical versus social control of editing. History The first generally recognized "wiki" application, WikiWikiWeb, was created by American computer programmer Ward Cunningham in 1994 and launched on c2.com in 1995. "WikiWikiWeb" was also the name of the wiki that ran on the software, and in the first years of wikis' existence there was no great distinction made between the contents of wikis and the software they ran on, possibly because almost every wiki ran on its own customized software. Wiki software originated from older version control systems used for documentation and software in the 1980s. By the mid-1990s these generally had web browser interfaces. However, they lacked the ability to easily create links between internal pages without writing HTML code. For WikiWikiWeb, the CamelCase naming convention was used to indicate internal links, without requiring HTML code. By the time MediaWiki appeared, this convention had been largely abandoned in favor of explicitly marking links in edited source code with double square brackets. Page names thus did not interrupt the flow of English and could follow standard English capitalization convention. Case-insensitivity on the first letter but not subsequent letters supported standard English capitalization conventions and let writers author their pages in ordinary English, with the linking of particular words and phrases afterward. This proved to be the critical change that allowed ordinary authors of English to write wiki pages, and non-technical users to read them. This policy was extended to other natural languages, avoiding the use of unusual-looking text or awkward capitalization that violates the language's own rules. Over the next 10 years, many more wiki applications were written, in a variety of