a Nova/WGBH, La Cinquième, Südwestrundfunk, Gedéon Programmes, Meridian, and NHK co-production ; produced for Nova by Providence Pictures, Inc. for WGBH/Boston ; written and directed by Liesl Clark
a NOVA production by the WGBH/Boston Science Unit in association with BBC-TV, NDR International Hamburg and Nederlandse Omroepprogramma Stichting ; written, produced and directed by Linda Garmon
a WGBH Science Unit Production by Debonair Production Company in association with La Cinquiéme ; WGBH Educational Foundation ; produced and directed by David Espar, Diane Hendrix & Michael Rossiter
A Rosetta Pictures production for Nova/WGBH and Channel 4 ; WGBH Educational Foundation ; written and directed by Christopher Rawlence ; produced by Emma Crichton-Miller