The Aliens novels are an extension of the Alien franchise. Up until 1998, the novels were published by Bantam Books and were all adaptations of various comics previously published by Dark Horse Comics. The most recent run of novels, which began in 2005, consists of original stories being published by Dark Horse Comics under their DH Press imprint.
The Predator novels are an extension of the Predator franchise, the most recent are published by Dark Horse Comics under their DH Press imprint. The first novel in the new series, Forever Midnight, was released in 2006 and proved a success (selling 1,000 copies a month) leading to further volumes being commissioned.
The Aliens vs. Predator novel series is a trilogy of novels that belong to the fictional crossover franchise of Aliens vs. Predator, based on the original Aliens vs. Predator comic book series by Dark Horse Comics.