http://images.businessweek.com/ss/05/06/sharing/image/sharing.jpgPPT_LOGO_4b
‹#›
Autodesk Confidential Information
Developer Days Online 
The Wine – Families
2009/2010 Comparison
Revit 2009
Revit 2010
Cannot run API commands while working in the Family Editor
Cannot create or modify family geometry, types, etc. using the API
Limited ability to query the contents of a family with:
•Family.SolidForms
•Family.VoidForms
•Family.Others
And other properties of the Family class
CAN run API commands while working in the Family Editor
CAN create and modify family geometry, types, parameters, etc.
Ability to analyze the contents of a family now comparable to what can be done with Revit project data
In 2009, while you are in Family Editor, you have no access to API at all, not possible to create or modify family geometry or types using the API and had limited ability to query contents of a family like solids, voids and basic volumes, basic read only possibility.  IN 2010, we have a whole new world using Revit API, we can run API commands while in Family editor, we can create and modify geo, types and parameters of family just like we have it in UI. Better possibility to analyze the contents of family and work with it.