How to Tag or Metadata Image Files Across Mac and PC

someone asked a similar question a few years ago, but I need some additional detail.

I'm looking to build out a searchable image library for my company. We have thousands of images and I'm trying to find the best way to "tag them" so-to-speak. The images are stored on a network drive and accessed by both Mac and Windows users. I work on a Mac and have Adobe Bridge, but not everyone accessing these images will. I've seen that in Windows, you can add tags to files for searching, and in OS X, you can add Spotlight comments (delimited by commas, it can be used as search tags), however, the 2 don't carry over across platforms.

Is there anything out there that may help in accomplishing this goal?

I'm not sure how XML works. If I apply tags in Bridge or another software, will these tags be available to everyone, on whatever platform, if they are using a software that can read them? How does this work? Do they simply open the folder in one of those programs and have the ability to search and filter?

Thanks in advance!