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 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injuries, almost incapable of using magic and haunted by the memories of her time on Earth, she becomes increasingly withdrawn from those who were closest to her.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!)

This story is a sequel to Stardust

When Equestria’s newest member of royalty asks for aid to be offered to her friends from abroad, the best and the brightest volunteer to serve. Captain Steel Song of the Dusk Guard are immediately mobilized to help XCOM defend their world from the enemies that besiege them. However, their first joint operation with the humans takes a turn for the worse and they quickly find themselves fighting for their lives against the full force of the monsters that threaten Earth.

(Stardust/Dusk Guard crossover)
(Coverart provided by a friend of Viking ZX!)
(While familiarity with both stories isn’t required, it is recommended)
(Many thanks to Arzoo for pre-reading!)
(All screenshots can be found at XCOM.wikia.com)
(Featured on 3/13/2013. Thanks everyone!)
(Now has it's own section on TVTropes as part of the Stardust series!)

In response to threats of a griffon attack on Equestria, Twilight responds with a letter detailing just why such actions would prove unfavorable for them.

Suri Polomare had every reason to be confident. A little theft here, a little deception there, and Fashion Week was as good as hers.

Too bad she didn't think about the long-pressured conscience of a certain timid assistant.

Inspired by the artwork of muffinshire.

Edit: So I've been told this story was featured. That's fantastic and I love you all for it. For srs.

Like every fresh young couple, shiny and new, Spike and Rarity's maiden voyage into the depths of romantic intimasea is met with rough tides. Naturally, it's all Twilight's fault.

Fluttershy has a problem: she keeps waking up with strange dreams. What has been going on? And what is that delicious metallic taste upon her tongue?

Warning: Contains Flutterbat and Silliness. Consult a Doctor if pain persists.

Supporting Cast: Rarity, Twilight, Rainbow Dash, Pinkie Pie, Celestia and Luna.

Edited by Level Dasher

This story is a sequel to The Eagle Has Landed

When President Nixon orders, you obey. And now that he wants Luna on the LM and heading home, how is Neil ever going to convince her to follow?
But it doesn't even get that far, as an innocent mistake endangers the mission.
And even as the mission is endangered, tensions are rising back on Earth. While the drama plays out in Mission Control, just what is going on behind the Iron Curtain?
No one knows, but it's certainly not conducive to Apollo 11's welfare.

Sequel here.

When Apollo 11 lands on the moon, Neil Armstrong utters his famous lines as his boots land in the lunar regolith, but when he turns around he finds something no one was expecting or had ever planned for.
There's an alien on the moon. And it's blue, four-legged, and staring at him.

Sequel here.

One foggy morning in Ponyville, the residents wake up to find their deepest darkest secrets sloppily written in red paint on their homes. No one knows who the culprit was, the only thing that the town knows is that it will not come off, no matter how hard you scrub. The town is baffled, humiliated, and in shambles. But no more than Twilight and her friends.

In a time where everything you fought to keep hidden is out into the open, will you embrace your faults or sins, or will you let them consume just who you really are?

Time to fess up, Ponyville.

Thanks to ThePristineEye for the coverart!

Also thanks to Kleora for editing!

Oh, and Skeeter The Lurker for proofreading.