PukiWiki is a Japanese Wiki software written in PHP, originally started as a fork of another WikiWikiWeb clone known as "YukiWiki", written in Perl. Due to its small base-install size, PukiWiki is considered a "lightweight" wiki application which also allows for expansion using its plug-in framework which allows for more advanced features seen in other wiki applications. With its default installation, PukiWiki uses flatfile storage of page and user information referenced by md5 hashes, which are used as unique identifiers.