HBO has acquired all U.S. broadcast and home video rights to Moms Mabley: I Got Somethin’ To Tell You. The feature-length documentary from director Whoopi Goldberg will premiere at the Tribeca Film Festival on Saturday and will debut exclusively on HBO later this year. The film explores the iconic stand-up comedienne’s legacy through recently unearthed photography, rediscovered performance footage and the words of comedians, entertainers and historians, including Eddie Murphy, Joan Rivers, Sidney Poitier, Kathy Griffin, Harry Belafonte, Bill Cosby, Quincy Jones, Jerry Stiller and Anne Meara. Mabley tackled topics such as gender, sex and racism, making her one of the first triple X-rated comedians on the comedy circuit. Once billed as “The Funniest Woman in the World”,  she performed on stage and in television and film up until her death in 1975. Goldberg also exec produces along with Tom Leonardis and George Schlatter.