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Source (game engine)

Source
Source engine logo and wordmark.svg
Developer(s) Valve Corporation
Stable release
Build 5595 / 2014; 3 years ago (2014)
Development status Active
Written in C++
Operating system Microsoft Windows, OS X, Linux, Android
Type Game engine
License Proprietary
Website www.valvesoftware.com

Source is a 3D video game engine developed by Valve Corporation as the successor of GoldSrc. It debuted with Counter-Strike: Source in June 2004, followed shortly by Half-Life 2, and has been in active development since. Source does not have a concise version numbering scheme; instead, it is designed in constant incremental updates. The successor, Source 2, was officially announced in March 2015, with the first game to use it being Dota 2, which was ported over from Source later that year.

Source distantly originates from the GoldSrc engine, itself a heavily modified version of John Carmack's Quake engine. Carmack commented on his blog in 2004 that "there are still bits of early Quake code in Half-Life 2". Valve employee Erik Johnson explained the engine's nomenclature on the Valve Developer Community:

When we were getting very close to releasing Half-Life (less than a week or so), we found there were already some projects that we needed to start working on, but we couldn't risk checking in code to the shipping version of the game. At that point we forked off the code in VSS to be both /$Goldsrc and /$Src. Over the next few years, we used these terms internally as "Goldsource" and "Source". At least initially, the Goldsrc branch of code referred to the codebase that was currently released, and Src referred to the next set of more risky technology that we were working on. When it came down to show Half-Life 2 for the first time at E3, it was part of our internal communication to refer to the "Source" engine vs. the "Goldsource" engine, and the name stuck.


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