Include Guards in C and C++: #ifndef, #define and #pragma once
A guard stops a header being pasted in twice. It does not stop it being defined twice. Tested examples, captured errors, and the pragma once myths.
C++ Programming
id Tech Game Engines — Complete History from Doom to id Tech 8
id Tech built the FPS genre: Doom, Quake, and thirty years of Carmack-grade engineering, now at id Tech 8. Every version, every game, all in one place.
Jade Engine: the Ubisoft Engine Behind Beyond Good & Evil and the Sands of Time
Ubisoft Montpellier built Jade for one game and named it after its heroine. It ended up carrying the Prince of Persia reboot. Here’s every game verified on it — and why the Beyond Good & Evil sequel isn’t one.
IW Engine — The Game Engine Behind Call of Duty
The IW Engine has powered nearly every Call of Duty for two decades. Here’s how it evolved from id Tech 3 into the technology behind the franchise.
Irrlicht Engine: The Open-Source C++ 3D Engine, Its Forks, and Its Status in 2026
Irrlicht is a small, open-source C++ 3D engine that still runs inside Luanti and SuperTuxKart. Here’s what it includes, a working example, and whether to use it in 2026.
GoldSrc: The Half-Life Engine’s History, Games and Legacy
The engine behind Half-Life and Counter-Strike: where the GoldSrc name came from, what Valve built on top of Quake, which games really used it, and its status in 2026.
Gold Box Engine: SSI’s AD&D RPGs, Every Game, and How to Play Them Today
From Pool of Radiance to Unlimited Adventures, SSI’s Gold Box engine defined computer D&D. Here’s how it worked, every game built on it, and where to play them now.
Godot Engine: The Free Open-Source Game Engine, Godot 4.7, and How to Start in 2026
Godot is the free, open-source engine behind Slay the Spire 2. Here’s what’s new in Godot 4.7, how scenes, nodes and GDScript work, a tested example and how it compares.
G3D Innovation Engine- A Teaching Game Engine
G3D Innovation Engine is a fully featured, cross platform game engine. This is a 3D engine written in C/C++. It is a commercial-grade, open source engine for different platforms i.e. Windows, Linus and Mac OS. The engine is licensed under BSD-2 license and mainly used for teaching purpose.
Gambryo – A mature game engine
Gambryo is a cross-platform game engine written in C++. It is a suit of several C++ libraries, plug-ins and run-time libraries. The engine supports several platforms like Windows, Android, Mac, Linux, iOS, Wii, Wii Ware, Xbox, Xbox 360, Xbox One, PS X, PS 2, PSP, PS3 and PS4.
Frostbite Engine — EA & DICE’s Game Engine: Games, Features & History
The Frostbite engine powers EA’s biggest games, from Battlefield to EA Sports FC. Here’s how DICE’s technology works, the games it drives, and why you can’t download it.
Exult – Free Game Engine
Exult is a FOSS (Free and Open Source Software) game Engine. It is written in C++ and runs on Mac, Windows and Linux. Exult was developed in 2004 to recreate a massive hit game of 1990’s called Ultima VII. It is created for the revival of Ultima VII (The Black Gate) and Ultima VII part2 (Serpent Isle) on modern PCs.