It is the year 2038, and the Earth is slowly being consumed by a space-borne monstrosity dubbed the Black Tide, which is using nanotechnology to remake the planet into something hideously alien.

Erin Olsen works for Project Harmonics, humanity's last-ditch effort to find a new world before the Tide can wipe them out. But when that world is found, and it turns out to be occupied, Erin will need to find the courage to face the unknown in order to save the inhabitants of both worlds.

(Many thanks to Easteu for the fantastic cover image for this story!)

Now with its own TV Tropes page

There is now a follow-up to this story: Sunflower - Side Projects
Sequel: Project Sunflower: Harmony

Every pony in Equestria knows the names Octavia Philharmonica and Vinyl Scratch. Every musician in Equestria knows and reveres their talent and most semi-jokingly complain that Octavia and Vinyl's relationship should count as a monopoly on musical talent. Very few know their early story, years ago when Octavia had only just left Canterlot Conservatory and Vinyl was... well, being Vinyl.

The Sequel to Number 12.
The Doctor and Twilight leap into the future, though it may be a far darker place than they envision. In the mean time somehow the Doctor keeps crashing around Ponyville, something to do with Fluttershy, but what?

A blue box has fallen out of the sky, and crashed right into Twilight's Library! A strange brown stallion, calling himself the Doctor stumbles out. Soon after, strange stone Pegasus are everywhere, one of resident weather ponies has vanished, and Twilight is tossed in the middle! The Doctor and Twilight have to find out what's going on, before it's too late!

Be Awed and Amazed by the tale of Sweetie Belle as she traverses the multiverse in search of her lost mentor and friend, Twilight Sparkle! Will she find her in post-apocalyptic Equestria? Or maybe in a strange world where everypony is the wrong gender? Or even where a Pony claims to be a human? Read as she journeys through very familiar worlds you might have read about... if you dare!

At this point in time all the main worlds to be visited have already been chosen. Thank you all for the suggestions, and I hope you enjoy the surprises!

Here's the official TSC:F Music Intro: The Sweetie Chronicles: Fragments

WDTP: S2/3-CE
You can also visit the TV Tropes Page which has spoilers!

After a long time--she would be more precise but Twilight has lost track of time--she emerges from the dark of the library. Her candles are burnt down to nubs. There is no food left in her pantry and furthermore, no coffee. So she goes to seek both.

And finds the town changed. Or is it Twilight who has changed?

When the Cutie Mark Crusaders dig up an ancient magical artifact, they unleash a spell on the town that allows everypony to see a "lie meter" floating above each other's heads. While attempting to solve the mystery, Twilight Sparkle has to analyze the tenuous balance between friendship and honesty. She doesn't like what she finds.

Based on a story idea conceived by theworstwriter
Written and posted with his permission

After the most important night of her career is ruined and its saboteurs not even so much as punished, Octavia's life changes. She begins to pursue a path that has never been seen before in Canterlot, where concertos and rhapsodies give way to controversy and rebellion.

A path where symphonies are composed with cans of spray paint.

Cover art used with permission by LuGiAdriel14

The Princesses find an alien creature barely clinging to life at the scene of a terrifying crash. Can the Combined Power of the Elements of Harmony save it, or more importantly, should they save it? Will the arrival of this strange creature tear Equestria apart?

TV Tropes
https://tvtropes.org/pmwiki/pmwiki.php/FanFic/Article2

Twilight Sparkle never was a Unicorn and she didn't even know it.
What happens when her true heritage comes to light? Will she willingly embrace it? Or will she be forced to?

Beware of spoilers in the comments!

Edited by uTTerAbsurdity, Zervziel, Stormwatch and Gwenio

Cover art by the talented Cartoonlion and colored by the equally talented Stormwatch, original can be found here

Click here for the Tvtropes page