In June 2014, Apple announced that the development of Aperture had been discontinued. Though the Aperture application would continue to work for years to come, it was time to plan to move on to a different photo management tool.
HoudahGeo can help with the migration process. Before moving away from Aperture you will want to safeguard geotags and other metadata currently stored with Aperture. HoudahGeo can copy these to industry-standard EXIF / XMP tags embedded within your JPEG or RAW image files. These geotags will be available for other photo management and editing tools to pick up.
Starting with macOS 10.15 Catalina, Aperture is no longer compatible with macOS. For many, this was a major reason not to upgrade their systems past macOS 10.14 Mojave.
Sticking with a dated version of macOS however, is not always practicable. Fortunately, there is another solution. The open-source Retroactive tool allows you to run Aperture and other discontinued applications on macOS Catalina and Big Sur. Thanks to Retroactive you can continue to use your favorite photo organizer. You can also use Retroactive Aperture to check your Aperture library after having migrated to a different tool. There may be an edit you would like to refine rather than start over elsewhere.