A 'Human in Equestria' story, but reversed.
And by that, I do not mean 'a pony in the human world'.
A human is in Equestria Equestria is in a human!

A quick one-shot. Hopefully it will entertain you a little.
It could have been made longer and more involved, but there wouldn't be much point to that.

Chinese Translation by forgivenlove

The nation of Equestria has been exploring their little slice of the universe for some time now. From launching probes into deep space, to landing ponies on the moon. Sending things beyond the grasp of their planet has become almost routine. However, with every mission into space, there comes a time when the voyage must end. What happens when Equestria experiences the end of a voyage that they didn't begin?

Updated and Revised on October 5th, 2014

In a world full of magic, mere words can pose a deadly threat. When simply reading a sign can instantly infect the unwary, and cases start to turn up all around Ponyville, Twilight Sparkle casts the only spell she can find that can give her the time she needs to find the cause of the plague. But then she has to figure out how to stop the epidemic... without being able to read.

Editing provided by Spabble
If you like this, try Rainbow Typhoon
Audiobook on YouTube and for download on SoundCloud
Spanish version translated by MIkimoco
Russian version

Something has happened to Equestria. Once a land of love and tolerance, it has been reduced to violence and tyranny.

Twilight Sparkle is the only pony who can remember how the world used to be. Even her former friends can't recall the time they spent together. All they know is distrust and hate.

And so Twilight began to spread her tale, in hopes that somepony would be reminded of the way things used to be. Unfortunately, her claims prove to be a threat to the existing social structures, and she attracts the attention of her former mentor.

I'm aware the story seems incomplete. I have no intention of continuing it at the moment.

A crossover with Homestuck: www.mspaintadventures.com. Knowledge of Homestuck is not required to enjoy the story, but such knowledge does help to explain a bit about what happened to Equestria.

Celestia: a filly of twelve. A cynical, hungry pauper, with a young sister to protect and feed.

But the food has run out. Winter has gripped the land for too long, and now the pair face starvation.

The cynic in Celestia knows she can't move the sun. But the child in her wonders... and so she tries.

(Inspired by the Donovan song of the same name.)

(Now with a dramatic reading here, by Crafty Arts, and here, by KeyframeProductions.)

(Now with a Spanish translation here.)

After several bloody years of war, we are about to defeat King Sombra. I almost wish we would have lost.

The storm is breaking on the Horizon.

It's been two months since the battle against Nightmare Moon. Luna is recovering, Celestia is busy turning the government back into a diarchy, and the Mane Six have returned to their lives. All seems well, but when Celestia discovers that half of the power of the Elements of Harmony have been transferred to each of the Bearers, she decides to send thirteen mysterious members of the Royal Guard to monitor them as they manifest and develop their new abilities.

The sins of a forgotten war still linger, and an ancient evil lurks in the shadows, just waiting for the right time to strike. The Mane Six suddenly find themselves once again at the heart of a conspiracy to bring about Eternal Night, and only by awakening their powers and realizing their full potential can they do anything to stop it. Friends both old and new will help them along the way, and an unseen force will guide them as it seeks to right a wrong made thousands of years ago. The Bearer's journeys will take them outside the borders of Equestria and into the world beyond, and when they return, they'll have the power and experience necessary to save the world and bring about balance in all things.

The Powers of Harmony TV Tropes Page (SPOILERS)
The Powers of Harmony Art

Thanks to Wildy71090 for the cover pic.

Ponies have spread to the stars thanks to advances in technology. In the advanced and luxurious Solar Explorer, Celestia travels to the first extra-solar colony world set up by her little ponies. Unfortunately, events elsewhere in the galaxy, unknown to them, have set in motion a cycle that has been repeated for countless eons… the reaping of sentient races. A Reaper dreadnought confronts the Solar Explorer, intent upon indoctrinating the leadership of the ponies and bringing them to heel.

Said Reaper quickly learns exactly why Celestia has earned the title Unconquered.

A Mass Effect crossover oneshot.

Now with a reading done by Scarlett Blade! Check it out!

The cultural ministry of Yakyakistan has decreed that season 5 of My Little Pony: Friendship is Magic needs more yaks and more smashing. They hope that you enjoy this new and improved version of historical events.

Thanks and/or blame to Majin Syeekoh for convincing me I should actually write this.
Thanks to Dubs Rewatcher for pre-reading and advice.

Celestia sends Twilight her last, greatest assignment. The lost masterpiece of Star Swirl the Bearded!

The spell that the greatest mage of all time couldn't figure out.

The spell given to her by the mare who thought releasing Discord was a good idea.

The spell that, upon closer inspection, seems about as stable as Rarity's emotional state and as safe as Rainbow Dash's usual workout.

... Maybe Twilight should double check with the princess first.

Winner of the Rage Reviews F*CK THIS PROMPT 6 contest. Prompt: "Equestria is getting a new Alicorn Princess."