Mostly for fiction and poetry, there's René Depestre (info in French at http://www.lehman.cuny.edu/ile.en.ile/paroles/depestre.html as well as a whole lot of Haitian authors, including nonfiction writers, listed at http://www.lehman.cuny.edu/ile.en.ile/haiti/paroles.html). I haven't read any nonfiction by Haitian authors but I'll poke around.