(written from a Production point of view)
Star Trek: Federation was an undeveloped Star Trek spin-off to be produced by Bryan Singer. Set in the year 3000, the show was to chronicle a period of decline and rebirth for the United Federation of Planets, spearheaded by a crew on a new USS Enterprise.
"Utopia as a goal is like the fire in a nuclear engine. Utopia in practice is stagnation; it's dry rot; eventually it's death. Which is precisely where we find the United Federation of Planets a few centuries after the last Age of Discovery."
Humanity has become complacent, and many worlds have left the Federation because of its Human-centric nature. Starfleet is stretched thin and many of its ships are outdated. A new enemy called the Scourge attack and destroy the USS Sojourner and two colony worlds. The only survivor is Lieutenant Commander Alexander Kirk. The authorities refuse to believe his story, a state of affairs that causes Vulcan, Bajor, and Betazed to leave in disgust at the corruption of the UFP, leaving it with only twenty systems under its control.
The Ferengi become the dominant power in the galaxy, and make money by spreading the Bajoran religion and making Bajor into a major place of pilgrimage. The Vulcans reunify with the Romulans. The Cardassian and Klingon societies have evolved into more mystical and less warlike cultures, though the Klingon Empire is expanding once more (but they are still on good terms with the Federation).
Admiral Nelscott commissions a new USS Enterprise to return the Federation to its goal of going boldly, but with the ulterior objective of finding the Scourge. After its captain and first officer are killed, Commander Kirk (third-in-command) is promoted to captain of a crew of four hundred.
After the cancellation of Star Trek: Enterprise in 2005, Singer, writer Christopher McQuarrie, and producer Robert Meyer Burnett met in December of that year and discussed their mutual desire to create a new televised iteration of the Star Trek series. 
They brought in novelist and screenwriter Geoffrey Thorne, who conceived and wrote a series proposal. "What I tried to do was go back to brass tacks," he explained, "and asked myself, 'What was Star Trek actually about? What were Gene [Roddenberry] and Dorothy Fontana trying to do when they first started the show? What was going on in the world at the time and what is the job of a good TV show?'" Thorne answered the latter question by concluding that, if the series was to be a "good" TV show, it needed to appeal to its mass audience and not rely on the viewers who would watch it simply because it was Star Trek. "What you want is a show that is competitive with the other networks that are not Star Trek," he mused. "I considered that to be my job." Thorne also believed it would be important for the series to deal with the fact that audiences and behind-the-scenes staff had felt Star Trek had become somewhat preachy with its universe lacking internal conflict and need for commerce. "But that's not how Star Trek was when it started; it was very rough and tumble and I wanted to get back to that [....] So I said, 'Utopia has occurred and everything has stagnated' [....] I pictured a Federation that had hit its plateau and stayed there for three hundred years," Thorne continued. That premise would allow for the new show to feature much of the same technology as had been depicted in Star Trek: The Next Generation, including old Federation ships. Thorne also had the notion of starting every episode with a video letter home from one of the crew; even though that crewman might not necessarily be in the rest of the installment, their correspondence at the start, in each case, would inform the events that followed. (The Fifty-Year Mission: The Next 25 Years, pp. 750-751)
Thorne's series pitch document was twenty-five pages in length, detailing the era of the show, the eight primary characters, and outlines of the first four episodes (which resolved the Scourge crisis but led into another one with the Klingons). Appendices were included, discussing the Enterprise's new technology (including a singularity engine and cloaking device) and using CG environments for parts of the ship. 
McQuarrie and Singer were to write and direct the pilot, with Burnett to produce alongside Singer's Bad Hat Harry Productions, similar to Singer's arrangement on House. The proposal was completed in 2006 and sent to Singer (who was in post-production on Superman Returns).  Noted Thorne, "Everyone seemed very happy with the pitch and were about to present it." (The Fifty-Year Mission: The Next 25 Years, p. 751) While the document was being refined for a pitch later in the year, in April Paramount announced development of Star Trek with J.J. Abrams, and the proposal was never given to the studio. 
Incidentally, the underlying theme of the Federation/Starfleet in decline has to some extent been adopted in the 2010s for both Star Trek: Discovery and Star Trek: Picard, where Starfleet in particular is turned inward on itself and plagued by severe paranoia and fear.
|Undeveloped Star Trek projects|
|Films: The God Thing • Star Trek: Planet of the Titans • Star Trek III • Star Trek: The First Adventure • Star Trek: IMAX • Star Trek: The Beginning • Star Trek 4|
|Series: Assignment: Earth • Star Trek: Phase II • Star Trek: Re-Boot the Universe • Star Trek: Federation • Star Trek: Final Frontier|
|Episodes: TOS • TAS • TNG • DS9 • VOY • ENT • DIS||Novels and reference books|