Wikipedia's open license fosters other innovative uses and presentations of its content. A spoken version is available for some articles in the Ogg Vorbis format, as the more widely used MP3 format is covered by software patents which encumber redistribution under a free license. Stand-alone versions of Wikipedia such as Lexipedia are available for handheld devices. SOS Children distributes the encyclopedia on a CD (2006 Wikipedia CD Selection). Published copies of selected Wikipedia articles are also available via PediaPress, a print on demand service. A project within Wikipedia is working on ""Wikipedia 1.0"", a collection of Wikipedia articles that have been verified for accuracy and are ready for printing or burning to CDs. The German Wikipedia has been distributed on DVD; print and digital versions of the English edition are being planned.