Identifying common objects between two or more applications

Question

Is there any way to identify common objects between two or more application. 
 We have more than 30 unused applications and many(more than 2000) unused objects. 
 We are planning to delete all the unused application and the objects which are part of those applications. 
 So we need to delete the objects in bulk, but there are some used objects which are part of those unused application. 
 
 For this I need to find the used objects in unused application by giving the active application name. 
 Is there any way to do this?

Mike Schmitt · Answer

This is a big undertaking that you must do very carefully (obviously). In *absolutely all* cases I'd strongly recommend you make a backup export of any objects before deleting them - perhaps by adding these objects to a brand new application first. I don't know of any *automated* way of comparing common objects between different applications, but I don't know why that would stop you from doing what you need here. 
 As a starter hint: The "unreferenced objects" functionality in an existing App Package shows objects that are not used anywhere (other than in an application). 
 Also as a reminder: deleting an application does *absolutely nothing * to the objects it contains - so if there are cluttery unused applications then those can, generally, be deleted safely without worrying too much about the objects in them. One tactic you could take, though, is before you delete any non-empty application, add its contents to a special new application you create just to store the objects in deleted apps - so one-by-one, add the objects from Unused App "A" to your new app, then delete Unused App "A", then do the same with Unused App "B", and so on. At the end your "deleted app objects" app will hopefully contain the objects from all the apps you deleted - useful at least for tracking purposes.