Flash video also supports captions using the Distribution Exchange profile (DFXP) of W3C timed text format. The latest Flash authoring software adds free player skins and caption components that enable viewers to turn captions on/off during playback from a web page. Previous versions of Flash relied on the Captionate 3rd party component and skin to caption Flash video. Custom Flash players designed in Flex can be tailored to support the timed-text exchange profile, Captionate .XML, or SAMI file (e.g. Hulu captioning). This is the preferred method for most US broadcast and cable networks that are mandated by the U.S. Federal Communications Commission to provide captioned on-demand content. The media encoding firms generally use software such as MacCaption to convert EIA-608 captions to this format. The Silverlight Media Framework also includes support for the timed-text exchange profile for both download and adaptive streaming media.
