Wildfire Games is an independent game development team made up of volunteers from all over the world. Wildfire Games started out as the small modding team that produced "Rome at War", the largest and most popular mod for Age of Kings in 2001. Since 2003, the team has been developing a standalone RTS game, 0 A.D., from the ground up.
Here is an uber high resolution screenshot from the gameplay video release for the Winter of 2007.