Although strong debate still rages about the veracity of both him and his story, it's extremely likely that John Titor was a hoax. However, it's agreed by most that it's an entertaining and very elaborately constructed hoax, largely because the Titor story was literate, reasonably consistent throughout but was supported by "Cargo Cult" Internet science that had little relationship to known concepts of the Special or General Theory of Relativity, Quantum Mechanics or black hole mechanics. It was also supported by pictorial evidence, including a blueprint of his "time displacement" machine, as well as a photograph of it in use.
Titor himself claimed to be a serving soldier who was recruited to a governmental time travel project. He was sent back to 1975 to retrieve an IBM 5100 computer which he claimed was needed to overcome a Unix bug - Unix-based machines no longer functioned in his time period (this is an actual bug related to the 32-bit nature of the Unix clock).
He arrived in 2000 at his own volition. Although he never stated his reason, it's agreed by many commentators that this was to see the Y2K bug play out. He left in March 2001 to return to his own time.
He claimed his time machine - a "C206 time displacement" machine - was created by General Electric. He transported it in a standard motor vehicle and the car also served as his vessel whilst travelling through time (it remained stationary throughout with the engine off). He claimed that the public is fully aware of time travel in his time period although some chose not to believe it exists.
Titor's references to his past effectively describe World War III taking place. This culminates in nuclear war in 2015 in which nearly three billion people are killed, largely within major world cities. He says the first inkling of this will become apparent in 2004/5 around the time of presidential elections.
The war effectively starts as a civil war in the United States which rapidly spreads to the rest of the world. Continuing Muslim/Jewish tensions are a contributing factor to the war but not the cause. The civil war sees those in the cities fighting those in rural areas (Titor fought on the rural forces, joining a "shotgun militia" when he was 13).
The war is effectively ended by Russia when it drops nuclear bombs on most major US cities, thereby securing a 'victory' for the rural force. Most major urban areas in the world are also hit by nuclear weapons in tit-for-tat retaliation. Europe, Africa and Australia are particularly badly hit in this regard and, Titor claims, are all-but destroyed.
Life in Titor's time sees people attempting to recover from the war and making progress. There are five US states (the seat of government is in Nebraska), and lots of local communities which form tight-knit groups where people help each other. Technology allows an Internet-like system and there's rapid rail transport between major cities.
However, water must still be filtered to remove radioactive particles and life is still harsh, with people expected to work in the fields to produce locally-grown food for part of their day.
Overall the John Titor story is entertaining. However on close inspection it seems to have been inspired by Pat Frank's nuclear holacaust novel, "Alas, Babylon."
Titor's writings are collected on varous websites and were formed from discussions he had with members on the following websites:
External links (which contain his postings plus discussions and analysis on the veracity of his claims):