Who collected and collated the holy Quran?

Answer 1

Ali (PBUH) was always with prophet Muhamamd (PBUH) and every verse revealed he memorized and wrote it on animal skin or boned. then before death of prophet he said to Ali (PBUH) when I died you should stay at my home and collect the parts Koran. so the answer is Ali (PBUH)

but other people who memorized Koran made their own Koran. near 500 people memorized all the Koran at time of prophet. Arabs amazingly had strong memory.

then othman standardized Koran and made a unique Koran in reading method (not in text, the text was the same in different Korans but different reading method)

Answer 2

The Prophet Muhammad (PBUH)