It is a popular ploy amongst Muslims to claim that – unlike other religious texts – it has never been changed or altered. This wouldn’t actually make any difference to its veracity or not, an old lie or untruth is still a lie even if it has lasted a long time or been copied a great deal. Its also not true. The Koran has been through several revisions despite being the youngest of the Abrahamic faiths.
Whatever Muhammed said to his followers is the first version of the Koran. Straight from his mouth to their ears and recorded somewhat haphazardly. The problem with oral preservation was understood quite early so Muhammed’s followers became literate (learning from prisoners of war ironically!) and compiled his ‘revelations’ all over the place. Muhammed died, so did a lot of his followers. It is impossible to know what was and wasn’t lost of the Koran in light of those events.
Previously a scattered and haphazard oral record of many parts, the first Caliph Abu Bakr decided to collect the Koran into a single volume. This is Islam’s ‘council of Nicea’ moment and the first instance of a ‘standardised Koran’. This was compiled and written by – amongst others – Jewish and Greek scribes. It was collected and collated from fragmentary records, oral history, writing scraped on camel bones etc. What was kept and what was discarded we’ll never know but this effort would seem to account for the disjointed and fragmentary nature of the Koran and the incorporation of Greek knowledge and tribal custom into the corpus.
Caliph Uthman Ibn Affan noticed differences as Islam spread in the versions of the Koran and Islamic beliefs from one place to another. The earlier written version (version 2) was used as a basis for the production of version three which, aside from minor differences, is the modern Koran today.