Broadcaster PBS has added its shows to those available on the US iTunes Store.
The company is offering documentaries and episodes from its prime time and kids' programmes through the service at $1.99 each.
US iTunes users can buy, download and watch shows including, Antiques Roadshow, Nova, Now, Scientific American Frontiers and PBS Kids programmes.
PBS President and CEO Paula Kerger said: "Working with our member stations and producers, PBS is excited to deliver a variety of PBS' award-winning primetime and kids' television programs through iTunes. The remarkable success of PBS podcasts on iTunes over the past year indicates that PBS members and viewers of all ages are enjoying the new, expanded access to the content they want, when and where they choose."
The iTunes Store began selling TV shows with five shows from ABC/Disney less than a year ago in October 2005, and rapidly expanded its library to over 220 television shows from over 40 networks.