Q: In this task, you're given a passage, further information available on a particular linked term from the statement, and a question. Your job is to generate the answer to the question by using the information provided. If there is no clear answer obtainable, output 'none'.
Passage: The film opens as South Park creators Trey Parker and Matt Stone leave New York City and the 2011 opening night of their Broadway production The Book of Mormon to return to Los Angeles to begin the fifteenth season of South Park. The documentary chronicles the production of the season premiere, "HumancentiPad", beginning the Thursday prior to airing. Parker and Stone, alongside producers Anne Garefino, Vernon Chatman, Bill Hader, and Susan Arneson, discuss ideas for the episode. Parker mentions his annoyance with downloading the latest version of iTunes, and being forced to comply with the software's long list of terms and conditions. The rant leads to ideas, with Parker instructing the storyboard team on how to stage a shot. The film covers various aspects of production, including voice acting, animation, lip sync, communication with standards and practices, character design, and editing.
Link Information: SoundJam MP, released by Casady & Greene in 1998, was renamed "iTunes" when Apple purchased it in 2000. The primary developers of the software moved to Apple as part of the acquisition Question: Who developed the piece of software that annoyed Trey Parker?
A:
Answer: Casady & Greene