Civilization IV

3 projects, 1 with public code: source release.

Projects

Civ IV: BtS SDK (CvGameCoreDLL C++ source) + Python game scripts

Source releaseC++ SDK (official, VS2003 toolkit) + Python 2.4 + XML130 starspushed 2026-10-11MIT licenserelease v1.18.4

The Dawn of Civilization mod for Civilization IV: Beyond the Sword, based on the popular Rhye's and Fall of Civilization mod.

GitHub

Civ4 BtS CvGameCoreDLL SDK

Source releaseMSVC 2003, Python 2.4

Firaxis shipped full CvGameCoreDLL C++ source (game rules + AI) and Python; mods like K-Mod/AdvCiv build on it

Civilization IV

Source releaseC++ (MSVC 2003) DLL + Python

Wikipedia: source-available (non-OSI license and/or partial SDK code); source released 2006 (partly) by/for Firaxis Games / 2K Games. In April 2006 the developers released the source code of the core game mechanic to the public with a Soft…

What you need

You need your own copy of the game: these projects ship code only.

Agent environments

Quick-AI-LLC/civ4-hermes-opponent

More on PC

GameMethodYearStarsLast push

PCMindustrySource releaseAgent environment201929k2026-10-11 PCosu!Source releaseReadable bytecode+1200719k2026-10-12 PCCommand & Conquer Remastered CollectionSource release202021k2025-01-16 PCRollerCoaster Tycoon 2ReimplementationAgent environment200216k2026-10-12 PCDune 2000Reimplementation199818k2026-10-11 PCAge of Empires IIReimplementation199914k2026-10-03 PCCataclysm: Dark Days AheadSource release201313k2026-10-12 PCCivilization VSource releaseReimplementation201011k2026-10-12

Found via en.wikipedia.org/wiki/Civilization_IV, Quick-AI-LLC/civ4-hermes-opponent, en.wikipedia.org/wiki/List_of_commercial_video_g, gamasutra.com/view/news/99858/Product_2K_Games_F, 2kgames.com/civ4/downloads.htm

GitHub data checked 2026-10-12. Notes are summaries from the research pass; the project pages are the authority.