GtkRadiant

Based on Id Software's open stance towards game modifications, their Quake series became a popular subject for player mods beginning with Quake in 1996. Spurred by user-created hacked content on their previous games and the company's desire to encourage the hacker ethic, Id included dedicated modification tools into Quake, including the QuakeC programming language and a level editor. As a game that popularized online first-person shooter multiplayer, early games were team- and strategy-based and let to prominent mods like Team Fortress, whose developers were later hired by Valve to create a dedicated version for the company. Id's openness and modding tools led to a "Quake movie" community, which altered gameplay data to add camera angles in post-production, a practice that became known as machinima.

Player modifications, or mods, change a game's art or gameplay to create alternative or entirely new games. From the age of Atari through the 1990s, video game developers were known vigilantly protect their intellectual property through copyrights, patents, and general secrecy.Id Software founders John Carmack and John Romero were instead excited when their Wolfenstein 3D was hacked to swap content into the game, and decided to help rather than hinder the hacker ethic of those who would modify their later games, including Doom and Quake.Doom added new graphical detail to its first-person shooter predecessors (wall textures, varied environments) and local, networked multiplayer, but in 1996, Quake too added better graphics in a fully 3D world but became known for its Internet-based, long-distance multiplayer. It popularized consumer graphics cards with its implementation of 3D rendering under OpenGL technology, and its dedicated developer tools encouraged users to create their own modifications, spawning a "healthy mod scene". Around the time of Quake's release, these user modifications became known as just "mods".

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