Somewhere near the middle of the Wall-E movie, audience members — those above a certain age — are reminded of the classic 1968 movie by Stanley Kubrick.
Spoilers below. This gives away major plot points. If you don't want to know what happens in WALL-E, or 2001: A Space Odyssey, then it's probably best not to read on.
Although there are references in the early part of Wall-E, the first overt hints appear when we meet the control computer, named Auto. Auto is introduced as a dim red light behind a small, darkened plexiglass hemisphere.
While that might trigger a subliminal memory, the realisation hits us full in the face, when we notice that Auto has sabotaged Eve's efforts to bring back a green plant from the planet earth. In theory, once the plant has been found, it should trigger a return to Earth for the whole Axiom ship and its cargo of humanity.
This sabotage happens because Auto has a higher command, unknown to the human cargo and the human crew. The presence of the plant brings the crew's desires and specific instructions into conflict with the higher mission.
Auto therefore has no option but to over-rule its human master and begin a sequence of events designed to eliminate all trace of the plant and its bearers from the Axiom ship.
This, of course, is the essence of the 2001 movie: computers are all very well, but be careful how you program them.
In Kubrick's classic, the conflict happens because the crew is unaware of Hal's real mission, which is to find the sentinel/monolith/black rectangle, whereas the crew think they are only on a mission to Jupiter. Hal 9000 resolves this first by killing the hibernating crew members and then by falsifying a malfunction and after the active crew goes out to fix it, prevents them from re-entering the main ship.
Kubrick's lesson — and to a lesser extent that of Wall-E — is that it is important to ensure that programming is clear, with no ambiguous or conflicting instructions which might lead to unforeseen outcomes. In both cases, the computer recognises the conflict between instructions and in each case, decides the conflict can only be resolved by eliminating the human problem. In 2001, Dave Bowman 'kills' the computer by removing its memory banks. Nothing so final is required in Wall-E, but the human commander utimately has to wrest control from the computer.
Auto is not quite as sinister, or as murderous as the Hal 9000 series computer, but for a kids' movie, she's quite scary enough. The voice of Auto is provided by Macintosh Macintalk. Sigourney Weaver did the 'PA Announcement' voice for the Axiom, but Auto itself had a purely robotic voice ('Macintalk' is credited on IMDB). Thanks to The Custodian for that. I had Weaver as voicing Auto. Oops!
The nods to 2001 continue with the music (Also Sprach Zarathustra and The Blue Danube) and finally, with a space-dancing routine. Kubrick has a small ship docking with a space station to the Blue Danube, while the dance between Wall-E and Eve is one of the more touching moments of the more recent movie.
Some have equated the limited dialog in Wall-E to a Buster Keaton or Charlie Chaplin movie from the silent era. I think the reference there is much more to Kubrick's masterly direction of 2001. Kubrick developed the sinister character of Hal through very limited dialog, and told his story through huge scenes and wonderful sets. Equally, it is one of the triumphs of Wall-E that the story is perfectly clear, even with the limited dialog. The two main characters end up as thoroughly developed, yet neither of them says anything more than his or her name.
From a production point of view, there is almost no dialogue in the early scenes of Wall-E, and dialog is sparse throughout. The same is true of 2001. The first scenes of Space Odyssey — with the apes — are entirely dialog-free. Similarly, Wall-E has no-one to talk to in his lonely vigil on earth, so we hear some dialog in the recordings of the Hello Dolly sequences, but apart from that, no dialog at all. As each movie progresses into space, the dialog is kept to a minimum both in Kubrick's epic and in this more modern movie.
This kind of referencing is no coincidence. In an interview at Pixar in June 2008, director Andrew Stanton said he aimed to create something in the spirit of Stanley Kubrick's 2001, Ridley Scott's Blade Runner and space-western Outland.
Other similarities between the two include one of the main characters taking a ride in a pod, which is intended to be fatal. Another is the fact that human characters are not well developed, while machine characters get better treatment. I also think the colour palettes and tones of the two movies are similar, the spaceships are both high-key white. There are other similarities, but I'll leave you, gentle reader, to discover them for yourself.
Interestingly, Eve was apparently designed by the iPod designer, Jonathan Ive.
Sources, further information