Load and save levels in Unity3D using XML files, that you can also edit manually easily.
<Item prefab="BlueCapsule" x="1" y="2" />
<Item prefab="RedCube" x="4" y="1" rot="45" />
<Item prefab="RedCube" y="-2" rot="30" scale_y="3" />
<Item prefab="GreenSphere" x="-4" y="-2" />
Navigate to Team Brookvale website for the full description and tutorial: