Abramson was one of the many aliases of the once-immortal Flint. This name was among the more well-known of Flint's aliases. (TOS: "Requiem for Methuselah")
Star TrekPocket Books titles have mentioned Abramson as living in the 22nd or 23rd century and claiming fame as a great scientist. In one novel, he is associated with Noonian Soong and helps him design plans for the building of a positronic brain.
According to Entertainment Weekly, initial storyboards for a Flint episode planned for the would-be fifth season of Enterprise - in which Phlox' discovery of his secret is the catalyst for his reluctance to discuss the past with Kirk, Spock, and McCoy a century later - suggested that the Flint Enterprise encountered, who may have been acquainted with Zefram Cochrane and Henry Archer, would have been Abramson.
The novel Uncertain Logic gives his full name as Willem Paul Abramson. The FASA RPG sourcebook The Federation mentions a William E. Abramson but it’s unclear if this is intended to be the same character.