The 1996 Personal Audio player incorporated a novel mechanism for automatically identifying and retrieving media files representing episodes in a series as those episodes became available. This mechanism was later widely adopted as the industry-standard technique called “podcasting.” The Personal Audio server stored a compilation file that described individual media files which represented episodes in a sequence. The compilation file was stored at a predetermined URL known to the Personal Audio player and was updated as new episodes became available. The client player could then fetch the current version of the compilation file from time to time when connected to the Internet, and download new episodes identified in the compilation file so that they could be played immediately on request, even when the client player was disconnected from the Internet.
Today, podcasts typically take the form of an industry standard RSS or Atom compilation file whose URL is stored by the client player device when the user “subscribes” to the podcast. By 2013, it is expected that more than 39 million users will listen to podcasts.
Personal Audio’s 1996 precursor to podcasting is described and claimed in Personal Audio’s U.S. Patent 8,112,504 and an additional pending divisional application, both of which are entitled “System for disseminating media content representing episodes in a serialized sequence.”