There's some interest in interactive media widgets that could be more complex than you can do with an image map and some hyperlinks:
- multiple images you can page through
- annotations with localized labels and hyperlinks
- audio/video components
- ability to export the presentations to be used outside the wiki
It might be useful to build on the IIIF Presentation API, which is in turn built on top of W3C Web Annotations spec for some lower-level components. The file format is JSON-based, and there are multiple GLAM institutions supporting it to various degrees. In principle at least it's meant to be interoperable, as long as we don't customize it too much people should be able to take the presentations we produce and reuse them in other viewers.
(Full disclosure: I [brion] am on the IIIF's A/V working group which is extending Presentation API to support audio/video.)
Would benefit from T187872 to implement an IIIF Image API backend.
A good implementation would include both an integrated viewer, and an integrated editor with on-wiki storage and versioning (either as upload files or via ContentHandler). Potentially it might be wise to support downloadable conversions as well (to flattened PDF or .odp)
See also T173346 for general IIIF+Structured Data on Commons ideas.