The Word Hoard
The Word Hoard was a large body of text (approximately 1000 typewriter pages) produced by author William S. Burroughs between roughly 1953 and 1958. It constitutes the main body of Burroughs' most experimental novels.
Material from the word hoard was the basis for Naked Lunch, The Soft Machine, Nova Express, The Ticket That Exploded, Dead Fingers Talk, and Interzone. Naked Lunch was edited by Allen Ginsberg and Jack Kerouac, whereas the other books were mostly edited by Burroughs himself, with some help from Brion Gysin.
Burroughs used the cut-up technique to rearrange the material in different ways, especially for the three novels that constitute "The Nova Trilogy."
The Nova Trilogy
The author has declared the three books The Soft Machine, The Ticket That Exploded, Nova Express form a trilogy, sometimes dubbed The Nova Trilogy or The Nova Epic. This grouping is indeed intentional, but comparing the books to the other material produced from the Word Hoard, there is sometimes more in common between Naked Lunch and The Soft Machine than between the three books themselves.
In The Beat Book from 1974, Burroughs claims that when he edits a novel, about half of the material is cut away and later recycled in the next novel. This explains the phenomenon of the plots and characters fading in and out from the different books.
The Nova Trilogy was intended by the author as "a mythology for the space age."