This story is a sequel to The Best of All Possible Worlds

For generations, humanity has dreamed of discovering intelligent life out in the stars. To say that ending that search in downtown Pasadena was a surprise would be an understatement.

Princess Luna had herself a simple mission: Track Twilight Sparkle and her friends through a malfunctioning portal to Earth, and get them out without being noticed. Luna had no desire to establish permanent relations, or even to stay and talk. After all, both princesses were convinced from previous experience that humans were nothing but trouble.

It appears that both parties have much to learn about each other.

Present-day follow-up to "The Best of All Possible Worlds". "Alternate Universe" tag is because it pretty quickly diverges from Season Two continuity.

This story is a sequel to Secret Histories

“To the precious peace-loving ponies of Equestria:

Has your life lost meaning in a world without Princesses?

Have law and order in your quaint little village collapsed under an endless onslaught of monsters and brigands?

Do you need a hero? Do you dare to be a hero in these dark and uncertain times?

Fear not, little ponies, for if you are brave enough, there is something you can do: Travel to Hoofington and spend a night at the Inn of the Prancing Pony.

I guarantee if you do, your life will change...forever.”

This is a story set hundreds of years before "The Best of All Possible Worlds", yet it was written after and influenced by the events of "Parade Coverage" and "Secret Histories". It was co-written with Hope. The cover illustration is largely taken from part of the fan art "First Day", by Harwick.

The "Alternate Universe" tag is because this story explores a different way that the events following the banishment of Nightmare Moon could have unfolded. As for the "Human" tag...well, that will become clear later.

This story is a sequel to The Best of All Possible Worlds

In school, everypony learns about the official history of Equestria, the acts of heroes and villains that made the world what it is today. But at home, everypony learns another, secret history, about how their family and theirs alone is at the center of Equestria's history, and how without them, the world will fall apart. This Hearth's Warming Eve, Twilight Sparkle and their friends will share their secret histories, and in this way discover that the bonds between them reach back far earlier than Rainbow Dash's first Sonic Rainboom.

This is a follow-up to my earlier story, "The Best of All Possible Worlds". That story was set centuries in the past, while this story is present day. If you're wondering where the humans came from, see another side story that is otherwise unrelated to this, "Parade Coverage". Despite that, I expect that this story stands alone. The story's set in an alternate-universe Season Three that branched off early in Season Two.

The royal court of Canterlot welcomes its newest member with open forelegs: the human philosopher Voltaire, from Earth.

On Earth, Voltaire is known as the greatest enemy of tyranny in the history of literature, and a legend in his own mind.

On Equestria, the court betting pool is giving him a week before the Princess banishes him to the Moon.

Note: This story doesn't have sequels per se, but there are a couple of short follow-ups set in the present day ("Parade Coverage" and "Secret Histories"), and a prequel of sorts in "At the Inn of the Prancing Pony".

TV Tropes page.

This story is a sequel to Rainbow Factory

Cloudsdale Weather Corporation has been running without incident for over twenty years. That is, until two foals manage to avoid being processed and find themselves in the haunted bowels of the massive facility. Can they make it out of the abandoned factory with their sanity intact? Will they uncover the secrets even a company as dark as the CWC is ashamed to keep? And what of the workers who help ensure that, in the end, not a single soul gets through...

Love the series? Buy the book!

—[TVTropes Article]—[Plagen Shiki's Reading]—[The Song Inspired by the Story]—

Rainbow Dash is a headstrong, athletic pony who is utterly faithful to her friends and doesn't keep any secrets from them. Or so she pretends. Yet a surprise visit from Twilight Sparkle is about to blow the secret wide open, and the multi-hued pegasus will find out just how strong their friendship is.

Note: This story was written in the week following the airing of "May The Best Pet Win", and well before "Read It and Weep" was even known about. As such it haws since been overtaken by canon, but most folk tend to like it still so I will upload it here so I have a bit of a presence on FIMfiction beyond "lurker #347,921".

This story also includes "The Unrelated Epilogue" which is a mini-story based on a loose bit in the main one that I felt did not stand on its own, but that I wanted up nonetheless. It has Luna, but not RD or TS.
Cover image is a screencap from the show.

What if ponies did poop rainbows? What would happen? What if only one pony pooped rainbows? What if that rainbow poop proved to be an incredible source of near limitless energy?

One day, Rainbow Dash looked down after recently using the restroom. To her surprise, her feces was multicolored. Twilight begins to experiment with the promising substance, only to discover a way to use it as an incredibly powerful energy source.

Rating Teen and Sex just to be safe. It talks about it (in a very scientific sense) but does not show it.

A rare colour combination of the mane and tale, or an extensive and secret dye job? Neither. Rainbow Dash’s mane is not fake, nor is it the one she was born with.
Around the camp fire —and between ghost stories— Rainbow recounts the tale of how she gained her polychromatic mane.

Several days after having a terrible nightmare, Scootaloo takes her final exam at the Cloudsdale Flight Academy, and with the help of Rainbow Dash gains insight into the nature of her own character as well as knowledge of the deepest secrets of the Rainbow Factory.
Upd: YouTube reading by linksbro1: link

A spectral maned horse of voice cracking awesomeness, commonly known as Rainbow Dash, travails upon flying her prismatic figure eastward beyond the purple mountains, as told by old friends, noble and wise and otherwise.

An accompaniment(?) to the original work, Austraeoh, by Imploding Colon.
Special Thanks to Fourths and the Noble Jury for Assistance in the Cover Art