This document provides an overview and reference for QE, a 3D game engine. It describes the development environment including DirectX, OpenGL and Visual Studio. It outlines the engine's directory structure and key files. It also summarizes input handling, adding functions and classes to the engine loop, and deriving from the qeUpdateBase class. The document provides examples of initializing input, remapping keys, and reading the keyboard buffer. It references important QE API functions.