Q:

How do I downgrade an iPhoto library from version 9 to version 8.1

I recently acquired an older Mac and am trying to copy an iPhoto library from a newer computer to it.  However, the older version of iPhoto refuses to open, telling me "You can't open your current photo library using this version of iPhoto... Pease quit and use the latest version of iPhoto."
However, upgrading to the latest version of iPhoto isn't an option.
I found some information suggesting I could downgrade a library to an earlier version of iPhoto.  However, it says to use the "Rebuild Library" command from the "Library" menu.  However, there is no such menu in my version of iPhoto.  I found an Apple on rebuilding the iPhoto library (http://support.apple.com/kb/HT2638) but the option that I seem to need: "Repair the iPhoto Library Database" does not appear in the "Rebuild Photo Library" dialog box I get on startup holding Command and Option, although the "Rebuild the iPhoto Library Database from automatic backup" appears but is grayed out.

A:

I believe that the command "Rebuild Library" you're looking for is not in iPhoto but is actually in an excellent 3rd party app called iPhoto Library Manager.
Here's a link to the documentation on using iPhoto Library Manager to revert to a previous version.
http://www.fatcatsoftware.com/iplm/Help/downgrading%20a%20library%20to%20an%20earlier%20version%20of%20iphoto.html 

