0 A.D. is a historical 3D real-time strategy game developed by Wildfire Games. It takes place between 500 B.C to 500 A.D. and focuses on economy and war management. 0 A.D. offers a variety of playable civilisations whose characteristics are based on real world history.
The game source code is licensed under the GPL and the media is licensed under the CC BY-SA license.
Multiplayer lobby released in Alpha 15
In 0 A.D., players start with building a base in order to develop their economy, research technologies and train an army. The game has a strong focus on the combat aspects of real-time strategy games. Therefore different units have to be built to create an effective army. Which in turn requires the harvesting of resources.
0 A.D. has a competitive multi-player mode.
The different civilizations (Athenians, Britons, Carthaginians, Gauls, Iberians, Macedonians, Mauryans, Persians, Ptolemies, Romans, Seleucids, Spartans) have distinct strength and weaknesses, which are based on real world history. For example: Being allied with Rome came with great benefits (as well as great peril). As an in game effect, allied citizen-soldiers gain a +10% attack when in Roman territory. 
|| Code Name
| Alpha 21
| New in Alpha 21:
- New Civilization: The Seleucid Empire
- New Maps
- New buildings and units
- New game modes
- New command for units: Patrolling.
- Reworked balancing, soldiers are now weaker against buildings, making siege weapons more important.
- Upgrading System for some buildings
- New building models
- Many improvements to the User Interface
- Windows binaries can now use more than 2GB of RAM
- The game now supports hosting on arbitrary UDP ports
| Alpha 20
| New in Alpha 20:
- New Maps
- Allies can use each others storehouses
- Introduces a technology to let towers attack units standing underneath the tower.
- New technologies for fishing.
- Loot resources that killed enemies carried
- New graphics quality settings
- Higher quality graphical effects enabled by default on higher-end computers.
- Idle worker button is automatically disabled if there are no idle workers.
- Credits screen
- New trees and variations
- Improvements for observer mode and replays
- View players network information in multiplayer matches
- Cinematic camera for rendering cut scenes
| Alpha 19
| New in Alpha 19:
- Units can now capture buildings and siege engines from enemy players.
- Two new victory condition modes: Destroy/capture all enemy structures to win, or destroy all enemy units to win.
- New Game Mode: "Ceasefire-mode", all players are unable to attack their enemies for a predetermined time at the start of a game
- Featuers to improve attack coordination between allies
- AI imporvements
- New Skirmish Maps
- Engine now supports eight times greater range of terrain heights
- Replay system
- New animals
- More different voices for units
- Improved path-finding for units
| Alpha 18
| New in Alpha 18:
- New Nomad Game mode: The players start with only a few units, and no civil center, and must build a base from scratch.
- Introduction of an In-Game Technology Tree
- Improved AI that supports saved games
- The player can toggle groups of units between marching in formation and breaking formation
- New buildings
- Improved performance
- Many improvements to the map editor.
| Alpha 17
| New in Alpha 17:
- Combat Rebalance
- AI opponents support naval maps
- Changed Fog of War
- Units can be garrisoned on Walls
- Multiplayer Lobby Profiles
- New Maps
| Alpha 16
| New in Alpha 16:
- Localization into more than 10 different languages
- Improved AI
- New GUI
- Additional art, music
| Alpha 15
| New in Alpha 15:
- Multiplayer Lobby
- Auras for unit bonus
- Debut of the Ptolemaic Egyptians as a new playable civilization.
- Skirmish Maps which are similar to scenarios, but can be changed easily.
- Improvements to the user interface
| Alpha 14
| Alpha 13
| Alpha 11
| Alpha 10
The idea of the project is around since 2000. The source code was released under the GPL and media was released under the CC-BY-SA in late 2009.