The XSPF file extension or the XML Shareable Playlist Format is based on XML or Extensible Markup Language dedicated for playing music on digital audio players on personal computer or any portable device. XML allows easier file sharing or sharing of structured data across various information systems, specifically through the Internet. The XSPF file extension was designed to make playlists portable for sharing data and playing it over Web browsers.The file extension XSPF format allows content resolution of playlists. Content resolution is the recreation of playlists on local machines based on a data management technique called meta-data. Before, the file extension XSPF format creation of playlists was composed of file paths only referring to individual titles of song. However, with the XSPF file extension, a content resolver automatically opens a XSPF playlist and then searches each song on a catalog, following the sequence format of creator, album, and title of the song. The content resolver then recreates the playlist with available titles that match the sequence.The XSPF file format was written in Actionscript 2 programming language primarily using the Adobe Flash Player. This programming language is mainly used in developing Websites and software, as well as some database applications.The XSPF file extension was written by Lucas Gonza, a developer of Webjay.org but is currently a subsidiary of Yahoo.com. The XSPF file extension originated from Webjay, however, Webjay did not provide a player for XSPF file format therefore the files could not be played. An independent developer produced a music player called XSPF Musicplayer; hence, there were two independent products needed to play the XSPF file format.Currently, the XSPF file format is used by various software such as XSPF Web Music Player, XSPF for Ruby, JointRadio, PHP4XSPF, Amarok, and Serpentine. After extensive tuning and debugging since February 2004, the format's version 0 was released on January 2005.