Game Engine 4 (UE4)

Game Engine 4, officially known as Unreal Engine 4 (UE4), was developed by Epic Games. It served as the flagship 3D creation tool and successor to the widely successful Unreal Engine 3, which powered many games in the Xbox 360 and PS3 era. It is widely used in modern video game development and real-time rendering.

Unreal Engine 4 relies heavily on C++ for its core programming needs. Alongside C++, it features a highly powerful visual scripting system called Blueprints. This node-based system allows designers to create complex game logic without having to write traditional lines of code.

UE4 has been used to develop some of the biggest games in the world, including Epic Games' own global phenomenon, Fortnite. Other notable titles include Square Enix's 'Kingdom Hearts III' and PUBG Studios' 'PlayerUnknown's Battlegrounds.' The engine was also used extensively for stunning tech demos like the original 'Infiltrator' reveal.

Epic Games made Unreal Engine 4 free to download and use for both hobbyists and commercial developers. Under the standard EULA, developers only pay a standard 5% royalty on gross revenue after the first $1 million per product per calendar year. This highly competitive pricing model carried over to its successor, Unreal Engine 5.