These distributions do not include certain packages or configuration settings that allow the playing of DVDs or MP3 files or the viewing of Adobe Flash content, for example. Packages that allow the playing of MP3s are available to download from official sources but cannot be included on the CD. Packages to enable the playing of DVDs include the libdvdcss algorithm. Although adding these manually is possible, it can be time consuming. This is a particular problem for distributions aimed at simplifying the desktop Linux experience.