WinCatalog

Digital Asset Management (DAM) is a catagory of software that manages your files. Especially important as we may amass hundreds of thousands of pictures across dozens of disks.

Wincatalog makes a thumbnail of image files, including mpo, so you can search disks even when they are not mounted. It also stores the files exif and other metadata. You can add metadata such as fields, comments, tags and make virtual folders.

It’s Windows only. Often on sale at BitsDuJour

I had asked for mpo support and the programmer added it with his next release.