The original name of Sage Vyasa, the author of Mahabharata, is Krishna Dwaipayana Vyasa. The word Vyasa means split, differentiates, or describe and he gets this name after He divided the Vedas in four: Rik, Yajus, Saman, and Atharva. But the actual name of the sage is Krishna Dwaipayan.
He was born of Satyavati, a fisher woman, and the wandering sage Parashara, who was the grandson of Sage Vasistha. Satyavati later married Shantanu.
Vyasa's complexion was dark and therefore he was referred as Krishna and the couple had the child on one the islands (dwipa) of Yamuna River