Marker is best known for his cinema-essays, a form of documentary "consisting of the evolution of a theme or an idea rather than a plot per se; or the film literally being a cinematic accompaniment to a narrator reading an essay." (Taken from Wikipedia) That sounds pretty dry, but Marker's films are beautiful, funny and smart.
Here's the trailer from Yannick Bellon and Chris Marker's documentary, Remembrance of Things to Come, which is included with the new releases.
Marker is celebrated as "the best-known author of unknown movies". These new DVD's should remedy the obscurity of these great films.