The development of advanced machines in Overworld has progressed to the point where primitive vehicles, engines, and heavy construction equipment are now commonplace. Most of these innovations were discovered after explorers penetrated the desert rain shadow in Erevil and discovered drow living under hovering mountains supported by magic crystals. By infusing these crystals with magical energy, it was found that they could lift incredibly heavy loads and drive mechanical devices.
With the advent of crystal engines, it's become possible to build massive cities with skyscrapers that are nearly a mile high in some cases. Other uses come in the form of clocks, airships, ground transport, and heavy machinery.
Overworld is currently undergoing a worldwide industrial revolution.
Despite the mechanical and industrial advancements being made, magic is still required to power these devices. With magic being rarely taught in structured form, most magic comes from inherently magical beings such as sorcerors, and by harvesting magically-imbued plants and animals.
Vast factory farms exist in many areas of Overworld for breeding dozens of types of magic creatures.