The Four Thirds System is a standard for digital single lens reflex cameras designed and developed to take full advantage of the characteristics of digital technology. Because lens and body mounting information is based on an open standard, photographers can freely mix and match camera bodies and lenses supplied by participating manufacturers.
The “Four Thirds Lens Joint Catalogue” was jointly compiled by the three participating manufacturers to provide a single source that would communicate the fun and versatility offered by this open standard. In addition to covering 24 of the exchangeable lenses supplied by the three participating manufacturers under the Four Thirds System standard, the 40 full-colour pages also provide a clear yet highly detailed analysis of the features of each lens, together with numerous examples of photographs.
The website will be updated with new information about the Four Thirds System standard from time to time as new lenses become available.
Source: Olympus Press Release