The DVD Forum, an association of companies that contributes to the development of the technology, has information for both users of DVD products and those interested in their evolution. There are a few frequently asked questions lists on the site, which mainly explain the basics of DVDs, contrast them with CDs, and describe the differences between various DVD formats. Some technical specifications are also provided on the site for people in industry. For instance, the "Guideline of Transmission and Control for DVD-Video/Audio through IEEE1394 Bus" can be freely downloaded, as well as general recommendations for DVD video, audio, and production.