Since the late-1970s, iconic horror author The Shining.
When once writing about the underwhelming CBS adaptation of his book Under the Dome, King recalled an old anecdote about the author James M. Cain, in which Cain pointed out that whatever happens onscreen, his books are still available to read as he wrote them. King than said he felt the same way about the adaptation, and one presumes he holds similar feelings toward adaptations of his work in general. No matter what any particular filmmaker does, his book remains intact.
King's love for movies is also well-known, and he's even written quite a few screenplays as the years have gone on, sometimes adaptations of his existing works and sometimes not. With that in mind, it's not surprising that King would want to encourage wannabe Hollywood directors to try and get their feet wet by adapting one of his own stories, and give them an easy, legal, path to do just that.
Want To Make A Stephen King Movie? You Can For $1
Stephen King instituted what he calls the Dollar Baby (or sometimes Dollar Deal) program around 1977, seeing it as an opportunity to help out young filmmakers, albeit over the objections of his ant. How it worked then and still works today is that King will allow an aspiring director to adapt one of his short stories into a short film, granting them the legal right to do so for a payment of only one dollar. Naturally, for a deal that good, there are some strings attached. Most notably, the Dollar Baby film cannot be screened for any type of commercial use without approval, and King himself is entitled to receive a finished copy after the final cut is complete.
Additionally, only a selection of King's short stories are available to adapt as a Dollar Baby at any given time, a list of which is available on his official website. This is due to King not being able to license out stories he's already made exclusive deals with studios to adapt into feature films or TV shows. Three Dollar Baby shorts ended up being released commercially on home video in 1986, although the company that did so came to a new deal with King to allow such a move. The films included Disciples of the Crow (an early adaptation of Frank Darabont.
A full list of completed Dollar Baby short films isn't publicly available, and it seems likely the only one truly aware of all of them is King himself. A few can be found on YouTube or other video sharing sites, but one assumes they're not allowed to be monetized on those platforms, otherwise the contract with King would be violated. Dollar Babies are also sometimes shown at film festivals. Still, even if one can't make money off them, adapting a Stephen King story is a great way for a hungry filmmaker to get their work noticed, and possibly move on to bigger and better things.