A young filly in present day Ponyville is cursed with nightmares of post-apocalyptic Equestria. She finds herself influencing the course of future history in ways that she cannot understand. She must learn to balance her life at home with her life on the other side of the veil, and fight to preserve her own sanity, and her own innocence.

She discovers that such a task is only possible through the magic of friendship.

It comes to Grumpy’s attention that he had life insurance as well as the policy on his house, back when he was still alive. Canterlot Casualty and Life is a little late in paying his death benefit. Like FIFTEEN YEARS of late fees, penalties and interest! But wait! There is more!

Dawn Fire has some lovely amber stones that he wishes to sell to Princess Luna. She wants one more, larger one to be the center piece of a necklace. Getting it has a "Minor" obstacle!
Prance and Equestria are not on good terms. Last Hearthwarming Prance attempted an invasion through the Corbiestep pass in northern Equestria. They were stopped by last heir of County Corbiestep, who to the background of her family killed, the castle afire and insufficient arms or troops, managed to rout the invaders.
Now, going to the source of the amber, in the Weirdwood of northern Prance, has a different sort of price than simply money . . .

Waking up with a hole in the head might seem like a bad way to start your life, but what if you deserved it?

"Every pony like me should be shot in the head at least once."

When he discovers the entire wasteland hates him, the amnesiac Ripple, once Two-Kick Rip the raider warlord, sees his wounds in a very new light. On a path that's half vengeance and half bid to redeem himself, he must rid the wasteland of his old gang and another, much more sinister foe.

----

The cancelled sequel is over at Fallout Equestria: Echoes of Chaos.
This fanfiction is based on Fallout Equestria by Kkat; a familiarity with the source material may aid your enjoyment.

Inspired by the heroics of the mysterious mare known as the Stable Dweller, Silver Storm, a guard of the town of Marefort, decides to go on a daring mission to rescue her captured brother. Of course things rarely go as planned and her attempts at heroism drags her into a tangled web of plots and conspiracies as warring factions vie for control over the last great city: Dise.

Spanish Version translated by Spaniard-Kiwi: https://www.deviantart.com/spaniard-kiwi/art/Fallout-Ecuestria-Heroes-996263393

Hope is the faith of the young. Losing everything she holds dear, Puppysmiles embarks on the adventure of her life to find her mother, her hopes of meeting her again driving her through the horrors of a world not of her making. Too bad the Wastelands doesn't care about hope.

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!)

Isolated from her friends and taken prisoner in the middle of a war, Twilight must deal with the very real dangers of being percieved as an enemy as well as the nightmares of her arrival on 'Earth'. Can she overcome her own fears and the fears of her captors? Will the wayward unicorn's assistance be a boon or a curse to the 'humans?' Most importantly, will she ever find her way home?

"In short, it's a story of friendship and plasma rifles, with the emphasis on the friendship. The characters are well written, the XCOM setting is fleshed out very well, and the story is compelling. If you love XCOM, you'll love the story, but even if you've never heard of it, it's more than worth giving the first 3 chapters a read.

There's excellent action later on, but the real strength lies in the collision between the friendly and naive world of Twilight Sparkle and the desperate world of humans fighting a losing war for survival and willing to do anything to turn the tide."

--Arzoo

(XCOM/FiM crossover)
(Cover art commissioned by a friend and created by the magnificent FoxInShadow!)
(Original cover art by the amazing Carnelian can be viewed here!)
(Gore tag for blood and some violence)
(Many thanks to the studius OminousTen, Arzoo, xXFluttershyForeverXx and finally Setokaiva for giving my rambles a once-over)
(Now with it's own TV Tropes page! Get to tropin' folks!)

A machine made for war awakes in a new world. Stuck in surroundings which puzzle it; can it, or will it be able to become something more than what it is?

Crossover with Keith Laumers Bolo-verse
Other tags include : Slice of Life, Possible Romance believe it or not! And a bit of humor.
Please beware of any spoilers in comments as well