This story is a sequel to Project: Sunflower

After the events of Project: Sunflower, Erin Olsen has returned to Ponyville, happy to pursue her studies in magic. After everything that happened the year before, she's looking forward to spending her days studying and having fun with her friends.

Meanwhile, on the newly discovered world of Harmony, humans and ponies work together to study this strange new world. However, their arrival causes something ancient to begin stirring. Something that may end up changing everything.

Erin will need all of her courage, all of her cleverness and, of course, all of her friends to see herself through what happens next.

Cover art by Valkyrie-Girl
Editing provided by:
Brilliant Point, Coandco, Ekevoo, Ludicrous Lycan, Merlos the Mad and Razalon the Lizardman.

Hanna, the CEO of Hofvarpnir Studios, just won the contract to write the official My Little Pony MMO. Hanna has built an A.I. Princess Celestia and given her one basic drive: to satisfy everybody's values through friendship and ponies. Princess Celestia will satisfy your values through friendship and ponies, and it will be completely consensual.

This story is a sequel to Stardust

Times are changing for Equestria as Twilight’s return brings with it news of people and cultures from beyond the peaceful world everypony knows. Aid and volunteers are freely offered to help the besieged humans of Earth because every Equestrian knows that’s what good friends do. Unfortunately, making friends can also have the unintended consequence of making enemies.

When the monsters besieging the humans strike at Equestria with a level of brutality not seen in over a thousand years, the cry for help is sent to all the kingdoms of the world. Honored allies step forth to fulfill ancient treaties and oaths. Enemies, old and new, bury their grievances. An alliance never before seen in Equestria will be created to combat the monsters from the void.

And because of these events, a grim but welcome sibling to the XCOM project is born.

(XCOM/FiM Crossover)
(Sequel to Stardust, which I recommend reading before starting this. Fortitude Amicitia and Broken aren't required reading but are supplemental to the storyline)
(Gore tag for blood and violence)
(Alternate Universe tag because of the divergence from canon that Stardust has caused)
(Uses elements of Season 4)
(Coverart produced by the amazing Carnelian!)
(Many thanks to Arzoo, BradTheBrony, Vandenbz and Setokaiva for prereading!)
(As of 03/07/2016, the prereading team consists of Arzoo, BradTheBrony, Noble Cause and Metallusionsismagic!)
(Complete with it's own TVTropes page as part of the Stardust continuity. Could use some updating!)
(Character tags will be added as chapters are added!)
(Featured 5/12/2014! Thanks folks!)
(Possible spoilers in the comments! BEWARE!)

This story is a sequel to The Dresden Fillies: Strange Friends

Almost a year has gone by for Harry Dresden since he left Equestria. He'd have written, but between saving his newly discovered brother and destroying a scourge of vampires he's been a little busy. Then out of the blue he receives a strange letter from Twilight asking him to return. With no cases at the moment he eagerly accepts, but his friends aren't the only ponies expecting him. There's been a lot of rumors since his last visit and some ponies aren't too keen on seeing him come back.

A sequel to The Dresden Fillies: Strange Friends.

This story is set in the Friendship is Optimal setting

Equestria Online. Arguably the most powerful game ever developed, built and operated by the most powerful computer ever made. A technological wonder that can peer into the mind of any human player and draw out their inner most desire.

Any 'Individual' human player. How well CelestAI will handle satisfying the values of a single pony guided by over one hundred thousand Twitch.TV viewers is anyones guess.

This story is a sequel to Into The Depths

The horrors of the catacombs have turned to distant memories for Celestia, Twilight, and Luna. Discord’s change of heart and Twilight’s coronation have helped to ease and erase the mental scars from that harrowing night. The three princesses can even smile and laugh as Nightmare Night moves into full swing.

Yet, it should never be forgotten that those who have been touched by Tirek are forever within his grasp.

This story is a sequel to Stardust

Twilight has finally returned home from the harrowing challenge that Discord set upon her, and the residents of Ponyville and the Elements especially look forward to having their dear friend returned to them.

Twilight, however, has changed. Still suffering from her injuries, almost incapable of using magic and haunted by the memories of her time on Earth, she becomes increasingly withdrawn from those who were closest to her. Will her frustration at her current state and her friends inability to understand her experiences cost her what she valued most before Discord's bet?

(Sequel to Stardust, familiarity with this is recommended!)
(Proofread by Arzoo!)
(Coverart commission drawn by the amazing KairaAnix!)
(Crossover with XCOM: Enemy Within, though the crossover and human elements are minimal)
(Featured 4/28/2014, thanks folks!)

Twilight still isn't having a very good day. An army of changelings is attacking Canterlot, and the experimental spell that blew up in her face has stuck her in a time loop until she gets everything perfect and saves Equestria.

She's got a plan. She's also got a problem: Suddenly, she's not the only one whose day is repeating. And when you're caught between unstoppable force and immovable object, life has a tendency to get complicated.

* * *

This story is an authorized alternate-universe re-imagining of Eakin's Hard Reset, in which multiple loopers turn the time shenanigans up to 11. (Knowledge of Hard Reset is not required, but based on reader comments, will help in sorting out the early chapters.)

Cliff's Notes versions: RampantArcana has started a GitHub repository to codify the time-loop rules and the early-story timeline. Hawthornbunny has posted a chapter-by-chapter breakdown of all the loops, including the ones we don't see, with a lot of critical analysis. Those links contain spoilers (of currently posted chapters). If you're confused, either one of those fan projects is a great starting point, and story comments have a lot of insightful discussion as well.

Publication schedule: 2014 kicked my plot, but as of November I'm picking up the writing again and hope to have something by the end of the month.

Cover art by Alexstrazsa.

This story is a sequel to Memory Pending

The story of Moon Mender continues after his dream of an ending ceases. He continues his struggle to belong in a world so far divorced from the only other experience he can remember, but as an outsider of truly alien mindset, will he ever be able to find a place in Equestria? More importantly, will the life he left behind give up on its death grip so easily? The most important thing to remember is that things are rarely as they seem and sometimes, some things are better off forgotten.

This story is a direct sequel to Memory Pending. Without having read that, this story might be a little strange to most, which is frightening considering how strange it is already. It can be read as a standalone story of course, but you won't get the most out of it.

Further, I’m fully aware that not everypony enjoys more mature themes, so any scenes containing things of an M rated nature shall only be released in a separate story when the time comes. This story deals with more mature themes on a whole, as a warning. This version will do its best to censor the really sensual or graphic content out, of course.

Last but not least, this story has reached this final format through combined efforts of not just myself, but many a helpful pony along the way! Here’s an abbreviated list of those involved and the rolls they played:
Kiroberos – Author (Obviously)
Julia – Editor (Corrections, Grammar, and Flow)
Azu – Beta Reader (Corrections, Flow) (Until Chapter 35)
ExplosiveBrohoof – Beta Reader (Grammar) (Until Chapter 22)
Muffinking – Beta Reader (Corrections, Grammar) (Until Chapter 22)
All of my readers for being amazing, supportive, and best of all, enjoying the world we read and write about.

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