This world is called Amestria where instead of magic being the major force behind things, it's science. Specifically steam science.

The Unicorn counterparts are called Engineers. They are an enlightened race who were the first to discover the power of steam and harness it. Compared to most other humans Engineers are extremely intelligent and creative when it comes to things pertaining to machinery and steam power. An average Engineer can be seen with various gadgets and devices on their tool belts for any possible situation.

The Pegasi counterparts are called Aviators and live in the flying city of Cloudsdale(Still called that since why not?). Due to the high altitude of their city, all citizens make use of steam powered wing packs for maneuvering through the city. They've also developed specialized machines that can give off electrical shocks like lightning, form rain clouds, and any other type of weather phenomena as their city is too high to experience rain itself.
The Earth Pony counterparts are called Forgers. They forge the steel used in all machines across the land. As such they are generally heartier and physically stronger than most other races.

A custom among the citizens of Amestria is crafting special runes that represent a person's passions/affinities or talents, specially crafted once someone realizes what these are instead of magically appearing. From then on it is also customary to wear either the rune itself, or have the design woven into their clothes somewhere.

2619807
I would read the hell out of this. Have a Pinkie.

2619853 I concur. Make this happen.