Letters. Everyone writes them, and they're not just for ponies. Be they carriers of serious news, friendly correspondence between pen pals, or declarations of heart and heartbreak, each one is written with a clear purpose or goal in mind.

Celestia uses them to try and keep her faithful student and friends in line, and try to keep an unbalanced world on the straight and narrow.

This is much harder than it sounds.

Now with an audio reading by Lady Tenkage!

Side Stories:

Old-Fashioned Bar Hoppers, featuring Celestia, Mayor Mare, and Granny Smith shenanigans.
Journal of an Adolescent Clone, featuring Sunny and Moony shenanigans since Season 5.

Twilight Sparkle, a ward of the crown ever since she accidentally turned her parents into plants, is dispatched by Queen Celestia to the small hamlet of Ponyville; the Unicorn has expressed fear that an eldritch Alicorn of the past will arise there. And when Twilight Sparkle fails to defeat the fiendish NightMare Moon in the two Queens' former palace of Concordia Arbos, the planet is plunged into night on one side and day on the other. With only shards of rock to her name and a band of ponies at her side, she sallies forth to bring back the Sun. She will traverse field and mountain, desert and labyrinth if she needs to. Will she be able to solve the mystery of the Elements of Harmony? Who was NightMare Moon, and what evils come to Equestria apart from her everlasting night? And why does Queen Celestia believe that making friends takes priority over everything else for Twilight...?

Can be found on TV Tropes.
Has a YouTube reading by our own Alchemystudent.

The Elements of Friendship, Book I: Harmony
The Elements of Friendship, Book IS [interlude one-point-five]: Bonds
The Elements of Friendship, Book II: Chaoskampf
The Elements of Friendship, Book IIS [interlude two-point-five]
The Elements of Friendship, Book III
The Elements of Friendship, Book IIIS [interlude three-point-five]
The Elements of Friendship, Book IIII

Diamond Tiara turns in a paper on pony magic.

Special Forces working dogs are highly trained, just like the men they serve with.
When the Russians need a veterinarian, they call Fluttershy.

A highly eccentric and overreacting stallion rants on live TV about the hundreds of things about Equestria that drive him nuts.

A lot of things in Equestria manage to piss Sheep off. From telemarketers, city jerks, public restrooms, and his co-host, The Great and Annoying Trixie. Apparently Equestria has a lot of unsolved problems...

That or this stallion is out of his bucking mind.

This is a self-insert! Sheep is myself Ponyfied!

Alright, listen up and listen good because I'm only going to say this once. We are not a highly classified government organization. We do not operate above the System, over it or beyond it. Our primary objective is not to monitor, license, regulate and police extrademensional activities and beings on this great country. These interdemensional beings are not cartoon ponies from a kid's show called My Little Pony: Friendship is Magic. We do not officially exist.

You don't exist.

Got that?

...

Never heard of it?

...

Good. Welcome to the U.S. Department of Strategic Extradimensional Enforcement

Inspired by Tales Of The Canterlot Deportation Agency: A Typical Day by Estee.

[Warning: Tags might be added and/or removed as the story progresses]

The U.S Recon sniper, one of the most deadly and stealthy forces of nature on the planet. However, when one of these shadow warriors ends up in Equestria, how will he be able to adapt and survive in a new environment fulled with ponies, monsters, and even a splinter cell group of terrorist plotting an attack on Equestria. All while lurking in the shadows and becoming a lethal phantom. Only he is capable of stopping the extremists plan to cause utter chaos.

He controls the trigger of fate.

Twilight Sparkle has a secret. Not one that can change the world or overthrow the Princesses. But it is one that hangs over her head every day. One that colors her every thought and action. Or at least, that is how it seems to her. But when a rainbow colored pegasus asks her out on a date, will she learn to see past it, or will her secret tear apart a budding relationship?

Inspired by the excellent fic Asylum by Daemon of Decay.

Takes place before "A Canterlot Wedding."

Thanks to SilverSugar for the cover art. You can check out her other works here