How to work as a team in Unity3D?

Hello,

How to make game with Unity3D with more than one developer?
Does Unity3D support SVN? I know that there is Asset Server but it’s not free, I really can’t get that service because I have a small group.

How about the v5 of Unity3D? Is there any improvement team-workers?

http://docs.unity3d.com/Documentation/Manual/ExternalVersionControlSystemSupport.html