Thanks to detective work by the team at Westeros.org, it's been revealed that a surprisingly large number of classic SF and fantasy projects are in development via the Startling Inc. production company. The company is run by Vince Gerardis, a producer on Game of Thrones.
Some of the projects have been known about for a while and some seem to be stuck in development hell. Most seem to be speculative options, with the realistic prospect of making it to the screen being unclear. Still, it's worth breaking down the projects on the list:
Ringworld (MGM/Amazon): based on Larry Niven's classic 1970 novel about a huge, ring-shaped megastructure completely enclosing a star. Optioned in 2017, it is believed this project was moved onto the backburner some time ago and is not currently in active development.
Wild Cards (Universal Cable Pictures/Peacock): see more here.
Dark Winds (AMC): A detective series based on Tony Hillerman's novel The Dark Wind. Originally in the works at HBO, but presumably sold on to AMC since then.
The Ice Dragon (Warner Brothers Animation): an animated feature film based on George R.R. Martin's 1980 children's story. In development since 2018.
Eon (MWM, formerly Madison Wells Media): likely a project based on Greg Bear's classic 1985 "big dumb object" SF novel, Eon, the first volume in the Thistledown series.
A Song of Ice and Fire (The Works): speculated by the Westeros team to be a live experience or show based on the novels.
The Unpleasant Profession of Jonathan Hoag (Phoenix): a project based on Robert Heinlein's 1942 novella.
Sandkings (Netflix): see more here.
Passengers (Groundswell/Endeavour Content): likely a project based on Robert Silverberg's 1969 short story about alien beings who possess human bodies at will. Unrelated to the 2016 Chris Pratt/Jennifer Lawrence film.
Inconstant Moon (21 Laps/Picture Start): a project based on Larry Niven's 1971 short story.
Dry (Bruce Cohen Productions/MML): this is more ambiguous; possibly a project based on Neal and Jarrod Shusterman's 2018 novel about climate catastrophe.
Hawksbill Station (First Generation): a project based on Robert Silverberg's 1967 novel about a penal colony established in the distant past, from where prisoners cannot hope to escape.
Dayworld (Warner Brothers Television): a project based on the 1985 novel by Philip José Farmer where a chronically overcrowded Earth is managed by having only one-seventh of the population active at any time, spending the rest of the time in suspended animation.
Roadmarks (HBO): see more here.
The Postman (Playtone/Warner Brothers Television): a new take on David Brin's 1985 post-apocalyptic novel. The novel was previously adapted - mediocrely - as a film in 1997 with Kevin Costner.
More Than Human (Good Banana/HBO): an adaptation of Theodore Sturgeon's 1953 novel in which humans develop superpowers which they can blend together to create incredible effects.
OK (Anonymous Content): No idea on this one.
Arabian Nights (Tomorrow/ITV): Presumably another take on the classic mythological story cycle originally known as One Thousand and One Nights.
Rose Hill (Leeding Media): There's several possibilities here, including Julie Garwood's Claybornes of Rose Hill novel series (previously filmed in 1997 as Rose Hill) and Pamela Grandstaff's Rose Hill Mysteries series.
PLAY (Dimitri Vegas): No idea on this one.
Weetzie Bat (Stampede/UCP): A film based on the Dangerous Angels novel series by Francesca Lia Block. Ana Taylor-Joy, Nick Robinson, Theodore Pellerin and Keiynan Lonsdale were attached to star and Justin Kelly to direct, but there has been no word on the project since 2018. It might be that this is a new take on the same idea (since Stampede and/or UCP do not appear to have been involved in the 2018 project).
Clean (Anonymous): A surprisingly popular novel title, making it hard to pin down what it's based on.
Sleepless (Stampede): Most likely, a project based on Nancy Kress's Sleepless trilogy (starting with Beggars in Spain) about a new generation of humans genetically-engineered not to need sleep, who rapidly become far more intelligent and capable than "sleepy" humans and threaten to supplant them.
Up the Line (Village Roadshow): a project based on Robert Silverberg's 1969 time travel novel.
The Mars Trilogy (Fox): a project based on Kim Stanley Robinson's multi-award winning Mars Trilogy of novels (Red Mars, Green Mars, Blue Mars); previously in development at Spike Television with J. Michael Straczynski, where it was dropped after being a poor fit for the network.
The Belgariad (City Hill): a project based on David and Leigh Eddings' five-volume epic fantasy saga (credited to David alone, but in later life he confirmed his wife's full involvement in the writing process). As a major epic fantasy work of the 1980s, it's been developed for adaptation several times but never quite made it into active development. Its prospects have probably not been helped by the recent revelation that the authors were child abusers who did jail time in the 1970s for beating and imprisoning their foster children.
Billion Dollar Boy (Phoenix): a project based on the 1997 novel by Charles Sheffield, in which a spoiled rich kid from a future Earth is abandoned on a remote space station and has to work hard to survive.
The Dying Earth (A24): a project based on the four-volume science fantasy series by Jack Vance. Hugely influential and important, The Dying Earth directly inspired Dungeons & Dragons (which uses the same magic system) and the entire "Dying Earth" subgenre of science fantasy.
Flood/Ark (Anonymous/Epix): a project based on the high-concept SF duology of the same name by British SF author Stephen Baxter, about the Earth becoming uninhabitable when a previously-unknown body of water in Earth's mantle is released into the oceans, causing catastrophic global flooding and forcing humanity to adapt or flee the planet altogether.
Montmartre (Stampede): No idea on this one, except possibly a project related to Picasso.
RPM (Infinito): No idea on this one either.
It's likely only a small number of these will ever make it to the screen, and it'll be interesting to see which ones.