Though never mentioned by name, based on information from The Animatrix (2003) the Machine City is actually called "Zero-One" and located in the Empty Quarter in Saudi Arabia. This, as well as Zion as the last human settlement, would imply most of the main action of the film franchise takes place in the Middle East.
In an unprecendented simultaneous global release, this film opened at exactly the same moment in every major city in the world on November 5: 6 a.m. in Los Angeles, 9 a.m. in New York City, 2 p.m. in London, 5 p.m. in Moscow, 11 p.m. in Tokyo, November 6 at 1 a.m. in Sydney, and at corresponding times in over fifty additional countries worldwide.
The street corner where Neo and Smith fight in the crater, is the same corner from which Neo made his phone call at the end of The Matrix (1999) - the corner of Pitt, Hunter, and O'Connell Streets in Sydney, Australia. You can see the phone booth to the right when they hit the ground.
Many of the "raindrops" in the final fight between Neo and Smith are actually single lines of Matrix code, similar to those on displays seen in the "real world" throughout the trilogy. This subtle effect was added to imply the Matrix was beginning to destabilize. This visual trick was easily seen on IMAX and larger movie theaters, but can be seen on smaller televisions as banded rain that seems to "jump" like static during close-ups of the fight scenes.
The name of the station between the Machine World and The Matrix is called Mobil Ave. Mobil is an anagram of Limbo, the traditional station between Heaven and Earth, according to Catholicism. This anagram has additional subtext since Keanu Reeves is dislexic.
During the final fight sequence between Neo and Agent Smith and also during the credits, the following Sanskrit sloka is recited in a westernised style: "Asatoma Sat Gamaya, Tamasoma Jyotir Gamaya, Mrityorma Anritam Gamaya", which means "Lead me from the unreal to the Real, Lead me from the darkness to the Light, Lead me from the temporary to the Eternal".
The key of the beginning theme you hear at the beginning of every Matrix movie (rousing strings and horn blasts) ascends by one semitone with each movie. The Matrix starts in the key of E, Matrix Reloaded in F and Matrix Revolutions in the key of F-sharp.
The "product placement" billboards in the subway chase scene were added in post-production - during shooting, the poster spaces were occupied by dilapidated posters for a fictional movie called "Burly Men", starring Keanu Reeves, Laurence Fishburne, and Hugo Weaving.
Only one full-size APU was ever built. It was completely rendered in Auto-CAD, and parts were made detachable, so that for scenes involving different pilots and APUs, the detail work could be altered. The full model weighed around two tons.
In the scene where Morpheus, Trinity, and Seraph are chasing the Trainman, an advertisement for Tastee Wheat can be seen. Tastee Wheat was mentioned in The Matrix (1999) when Mouse was trying to describe the food in the real world.
Gloria Foster died before she could complete any scenes for the third film, as well as Enter the Matrix (2003). Mary Alice took the role of the Oracle for both the third movie and the game. In "Revolutions", the initial conversation when Morpheus and Trinity meet the "new" Oracle was adapted to reference her changed appearance. The alternative was to have Morpheus and Trinity pretend not to notice, which perhaps would have been even more awkward.
The ship referred to as the Hammer was actually named the Mjolnir, after Thor's hammer. The hammer in the Norse legends always returned to its master, sparking lightning and thunder along the way. Like the hammer, the ship returned to its master (Zion), with its own lightning and thunder.
The late Gloria Foster and her replacement Mary Alice had played sisters in a long-running Broadway play, something which Casting Director Mali Finn remembered when she was looking around for a replacement for Foster.
Maggie and Captain Rowland both briefly mention the term "VDTs" to describe a possible cause to what happened to Bane, and why he has self-inflicted cuts (not knowing that Bane is possessed by Agent Smith). However, VDTs are never defined or explained throughout the entire movie. Several sources claim that VDTs stand for "Virtual Delirium Tremens", which is the virtual form of "Delirium Tremens", a form of delirium caused by the absence and/or withdrawal of certain substances.
Zion, from Hebrew, refers to the citadel in Palestine, which was the nucleus of Jerusalem, or the Jewish homeland that is symbolic of Judaism, or of Jewish national aspiration. However, the word has also been adopted by the Rastafari, referring to their promised land (which is thought to be Ethiopia), and given the vibe, music style, robes, et cetera. of the underground dwelling of Zion, this is probably the meaning that inspired its inclusion in the movie.
Sati is the ancient Hindu practice of a widow immolating herself on her husband's funeral pyre. This practice is now illegal in India. According to Hindu mythology, Sati is the name of a Hindu goddess who burns herself, as she could not bear the insult heaped upon her husband Lord Shiva.
In the score for the first film, some cues were given names which were anagrams of "The Matrix" or "Wachowski Brothers". Here, the cue backing Neo and Trinity's approach the machine city is named "Saw Bitch Workhorse".
When Neo goes to see The Oracle in her apartment, the jazz standard "I'm Beginning to See the Light" is playing in the background; a different version of the same song also plays in the corresponding scene in The Matrix (1999).
The highway chase scenes were filmed at the closed Alameda Naval Air Station (Latitude 37°47'26.69"N Longitude 122°19'8.08"W). The main East and West runway, and part of another, were partially repaved and striped as a restricted-access highway, complete with entrance and exit ramps. The "sound barrier" walls restricted the viewing angles, and made it easier to insert a CGI skyline. Satellite and aerial imagery still shows the remains of the highway, but it's very clear with a viewer that shows past images (circa October 2002).
Composer Don Davis thought it would be wasteful for the choir to be singing simple "ooohs" and "aaahs" during the climactic battle cue, "Neodämmerung". (In one interview he joked that he would have had them sing "This is the one, see what he does".) He asked that the Wachowskis (Lilly Wachowski and Lana Wachowski) to bring him some sort of text, appropriate to the movie, which the choir would sing. They returned with extracts from the Upanisads, which reflect the themes of the trilogy. The full lyrics of Neodämmerung are available on Davis' website.
While Trinity is chasing the Trainman in the subway, an advertisement for Powerade can be seen. When The Matrix Reloaded (2003) was released in theatres, Matrix-based commercials for Powerade aired on U.S. television.
Before she could film her scenes, Gloria Foster passed away, and The Wachowskis had to re-cast the role of The Oracle, which Mary Alice was cast. The Wachowskis decided to establish that, in The Matrix universe, programs living in The Matrix can change, and choose their forms and appearances.
The name of the climactic battle cue, "Neodämmerung" is derived from the German word Gotterdämmerung, literally "twilight of the gods". It was the title of part of Richard Wagner's opera "Der Ring des Nibelungen" ("The Ring of the Nibelung") on Norse mythology. Gotterdämmerung told the story of the Ragnarok or Ragnarokkr ("twilight of the gods" or "fate of the gods"), a final, fatal battle which destroyed the home of the gods - and the gods themselves - forever. Even though they knew what would happen, the gods fought for the survival of mankind. The title is appropriate not just for its thematic content, but also Wagner's strong influence on the music of this movie.
Another similarity with Frank Herbert's Dune is that the protagonist in Dune (Paul) is blinded towards the end of the story but it's still able to "see" the world around him through perfect prescience.
In The Matrix (1999), when Morpheus tells Neo the story about The One, he states that The Oracle prophesied The One's return and his hailing would bring about the destruction of The Matrix, and end the war between man and machine. At the end of the movie, The Matrix is not destroyed when an assimilated Neo destroys Agent Smith once and for all.
A teaser trailer for both The Matrix Reloaded (2003) and The Matrix Revolutions (2003) was released, which we got a glimpse of all the humans being freed from The Matrix and waking up and emerging from their slime pods. That doesn't happen at the end of the movie.