One of the better sociopolitical rappers of the late '80s and early '90s, Def Jef (born Jeffrey Forston) released an excellent debut (1989's Just a Poet With Soul) and a mildly disappointing follow-up (1991's Soul Food) before going into production. When he left the MC spotlight, he worked on records by a number of artists -- as a producer and remixer -- including Nas, 2Pac, Snoop Dogg, Nadanuf, Boss, Bone, and Shaquille O'Neal. He made short appearances in the films Downtown (1990) and Deep Cover (1992), and he also remained active as the music supervisor for MTV's Lyricist Lounge program. In 2002, he and his Kontrol Freaks production unit put together Kontrol Ya'self, a piece of audio software with beats, samples, and tracks.
Source: http://www.allmusic.com/cg/amg.dll?p=amg&sql=11:aifwxq95ld6e~T1