If only for his unforgettable feature films, such as The Time Machine,  War of the Worlds, When Worlds Collide, and tom thumb (to name  a few), George Pal will be remembered as one of the most gifted directors  of fantastic cinema in history. Ironically, this popularity as a feature-film director  usually overshadows Pal's great contributions to the field of stop-motion animation. 

George Pal (February 1, 1908 – May 2, 1980), born György Pál Marczincsák, was a Hungarian-born animator and film producer, principally associated with the science fiction genre. He became an American citizen after emigrating from Europe.

George Pal's PUPPETOONS averaged eight minutes in length, requiring some 30,000 single frames (pictures) and 9,000 individually hand-carved wood figures for each frame of film. Their production was similar to that of a two-dimensional drawn cartoon.

WATCH A SHORT FILM FROM 1938

The technique of the replacement figure puppet was really Pal's invention and stop motion animation was used in some form or another in every one of his films. There is stop motion in DESTINATION MOON, THE TIME MACHINE, 7 FACES OF DR. LAO and THE WONDERFUL WORLD OF THE BROTHERS GRIMM. This technique is where it all started and the same basic process is the building block of all computer CGI today from JURASSIC PARK to TOY STORY.

George Pal inspired countless artists and writers and filmmakers, who, in turn, inspired scientists and astronauts, whose amazing journeys into space during the past 20 years have inspired a whole new generation of science-fiction creators. 

A nice tribute page is here.