Mac Platform: Intel
OS version: 10.11 or higher
Improved display of library version numbers for brand new versions of Photos
We now relaunch Photos periodically when merging to work around a bug where Photos would start refusing to import photos after a large number of consecutive imports
Fixed a bug when copying a folder that lives inside another folder that would cause the folder and its albums to not be recreated in the destination library
If Photos crashes after importing a batch of photos, we now relaunch it and restore the photos' metadata if possible rather than just moving on to the next batch
Fixed a crash that could occur after cancelling a library duplication
Fixed a crash that could occur after migrating certain iPhoto libraries to Photos
If Photos crashes while adding duplicate photos to an album, we now relaunch Photos and continue adding the rest of the photos
Fixed an issue where photo dates could be shown as 1/1/2001 if they were missing time zone info
The completion message shown after finishing Find Duplicates now displays correctly
Fixed an error that could occur when finding duplicates if a library has an empty name
Albums created for duplicate photos are no longer placed in a subfolder, to make them easier to find
Courtesy of C.O.R.E.
When using the Photos app to organize photos on your Mac, PowerPhotos allows you to break your photos up among multiple Photos libraries, rather than having to store all of your photos in one giant library. You can easily switch between libraries, or just browse the photos in your libraries directly from PowerPhotos, without having to open each library in Photos. PowerPhotos also supports searching across all your libraries at once to help track down a particular photo.
If you use iCloud Photo Library to sync photos with your other devices, splitting up your library can help save on iCloud storage costs. Use a single library to hold a smaller collection that you sync with iCloud, while keeping the bulk of your photos in separate libraries so they don't take up space on iCloud.
PowerPhotos can analyze your libraries for duplicate photos, showing them to you side by side and letting you get rid of extra copies of photos that you no longer need.
More info: http://www.fatcatsoftware.com/powerphotos/