Vaisampayana was a student of Vyasa. He was the first person deputized by Vyasa to retell the epic Mahabharata, on this occasion to King Janmejaya, grandson of Parikshit, and great grandson of Abhimanyu, hence a descendant of the Pandavas. Since Parikshit was as yet unborn during the events of the Kurukshetra, it would seem that he would have little first hand knowledge of the events, and his mother Uttara, herself just a teenager, could not have been very much wiser.
Just as Janmejaya learnt his own family's history from the deputy of a chronicler (a venerated one no doubt), the story we know today to be called Mahabharata, is largely based upon the authority given to the writings of Kisari Mohan Ganguli, who himself based those writings upon the translations of one Max Muller. Nevertheless, we present to you, after much effort and toil, in a very thin slice, another rendition of this old, old story, the Legend of Vyas. Enjoy.