Twilight becomes Princess. Trixie doesn't cope very well.

This is a fic based on the Time Loop Files, the format of which was first codified by Innortal on fanfiction.net.
Here's a brief guide.
The basic idea is, one character (the Anchor, usually the main character of a fictional setting) is looping back to the very first moments of their parent series every time either they die or some kind of time limit expires. They of course end up monumentally stir crazy given enough time.
Eventually others start to loop as well.
The reset is not always perfect. Sometimes a loop's history will be different to the "prime" loop, or canonical plot.
"Crossover" or "Fusion" loops also occur, randomly. These can involve the home loopers having a guest, or the anchor for one universe spending time in another, or replacements of one character by another.
Vacation Loops are where the Anchor (or others) decide/s "buck it" and lets off steam by doing whatever comes to mind. There's little or no attempt to maintain the original timeline.

In addition, and particularly more recently, it should be known that this story has a collaborative element to it - people may submit loop ideas or loops, ideally at the Spacebattles thread (a link to the current version of which is on the Trope page), and they may become included.

There's two page image options, thanks to Filraen - the current page image has been edited by the original creator from this work of theirs.. The other one is here:
http://hourglass-vectors.deviantart.com/art/MLP-Loops-466030169

This story is a sequel to A Stitch in Time

Having discovered the message left for her by Star Swirl the Bearded in the distant past, Twilight once again finds herself caught up in the middle of a struggle against forces far greater than herself. In order to even stand a chance she'll need to travel further and wider than she ever has, and forge some unlikely alliances with old enemies. All to bring down the powers that have manipulated and shaped her entire life, and retake control of her own future.

The conclusion of the Time Loop Trilogy, which began with Hard Reset
Available in Spanish thanks to dgs1993
Series TV Tropes page

Equestria is a land of rainbows and pastel-coloured ponies, where friendship is a tangible force and villians are redeemed as often as they are defeated.

It is truly a land of magic, but even more than that, it is a land of stories, from the mundane anecdote between friends to the world-spanning epic. And every story has a happy ending.

But a happy ending doesn't always mean a happy beginning, and it certainly doesn't mean a happy middle. Celestia has manipulated Equestria for over a thousand years to ensure that the dark times are as short and as painless as possible - though doing so may mean breaking every one of the tenets of harmony she preaches.

When faced with a choice between seeing Equestria fall to darkness with the promise of salvation, or fighting to stop the catastrophe by sacrificing the guarantee of a happy ending, Celestia holds the fate of her little ponies in her hooves as never before.

A behind-the-scenes look at Celestia and Luna's actions throughout Season Three.

Twilight gets drunk and ships Rainbow Dash with everything in the universe.

Rainbow Dash is not amused.

A terrible affliction has befallen the peaceful town of Ponyville, and the lavender unicorn and her friends are right in the middle of it! And the edges of it. Heck, it's pretty much lavender unicorns all over.

A story unrelated to anything.

This story is a sequel to π

After Twilight Sparkle made her biggest secret public much earlier than she'd originally planned, the lives of the Element-Bearers and their closest friends somehow managed to become even more complicated than they already were. Yet despite the flurry of all of the added activity this brings, Princess Celestia decides to undertake a particularly ambitious project: the reformation of Discord. She delegates the task to Penumbra Noctis, who, more than anypony else, can empathize with the draconequus' situation, and who is therefore best suited to showing Discord the magic of friendship. On the surface, it's a very reasonable plan.

Unfortunately, Discord has never had much patience for reason.

This is the fifth and final story in The Petriculture Cycle. Reading the first four stories, which begin here, is highly recommended.

Artwork by Page Turner. TV Tropes page by an unknown number of anonymous persons on the internet.

When troubled dreams lead to onstage accidents, Luna advises Trixie to think deeply on the magic of friendship. Trixie ponders her errors and realizes what she must do: swallow her pride, atone for her misdeeds in Ponyville, and befriend the ponies she has wronged...

... and then the power of the Elements of Harmony will be hers!

Apple Bloom is left to handle the majority of the work on Sweet Apple Acres since Applejack and Big Macintosh have to leave to help out on another family farm for a couple of weeks. Granny Smith is helping out wherever she can, but the majority of the labor rests in Apple Bloom's hooves. While she's not the inexperienced filly she was years ago, does the young mare have what it takes to run the Apple family farm in Ponyville while her two older siblings are away, or will the monstrous load of work be too much for her?

NOTE: This work began before season 3 commenced. Certain elements of it, therefore, will clash with some of the developments of season 3 and onward (including things like Princess Twilight, the fate of Apple Bloom's parents, cutie marks, etc). With that in mind, enjoy!

"My dear Twilight Sparkle,

Thank you for your recent letters. And I must apologize to you first and foremost that I have not responded back in kind to each and every one. I imagine has this concerned you, but please don't worry. Things have been very unsettled here in the castle as of late. Princess Luna has been researching Equestrian history, and I find myself in a strange kind of mood..."