Eclipse .PSF文件的结构

Question

有人可以解释Eclipse .PSF文件的结构：

<project
  reference="1.0.1,file:///D:/Local/Projects/com.com.someproject.name/trunk,
  com.com.someproject.name,906854a82af700161d10d93c2fba605a;
  file:///D:/Local/Projects/com.com.someproject.name;
  file:///D:/Local/Projects/com.com.someproject.name;
</project>