Krakauer's version of the events, but apparently actually researched it out and tried to put together the most accurate portrayal they could. I've read all the written accounts from people who were there that I could find and the movie comes across as being very close to what I believe the true story is. IMO, Anatoli Boukreev's, Beck Weathers', and Ed Viesturs' versions of the events are very similar and are probably the most accurate. Especially Viesturs' since he was there but was technically a third party witness. Rob Hall and Scott Fischer were two of his closest friends and he was lower on the mountain so his brain was working better while he was witnessing the whole debacle as it unfolded.

The mere fact that Jon Krakauer doesn't like the movie tells me that they did something right. The movie portrays him the same way everyone who was there described him and he doesn't like it one bit.

http://www.theguardian.com/film/2015/sep/28/jon-krakauer-into-thin-air-opinion-everest-movie