These utterances of texts from a book are created by a voice synthesis program automatically. They are delivered in three ways: as single MP3 files, through a podcast (RSS), and in a zip file with the DAISY format. MP3 files can be played on your computer or mobile player. For those who drive can be useful to record a CD player and listen in the car. The podcast can be opened with an aggregator (see list of aggregators), which automatically downloads all MP3 files in the computer/mobile device to listen to when we want. The DAISY format was initially thought to facilitate access to content for people with visual disabilities, but is becoming more and more popular among the general public. It allows, among other things, browse the contents. It is necessary to use a special player. The DAISY consortium provides a list of devices and other programs.