It seems like the edge server is available for free as an open-source stack, in a VM.
https://www.rsna.org/practice-tools/data-tools-and-standards/image-share-validation-program/developer-tools
Open Source software:
https://thairis.net/
https://librehealth.io/demos/
How do they communicate with PACS, acquisition systems, EHRs...?
https://www.ramsoft.com/pacs-radiology-information-systems/
DICOM (Digital Imaging and Communications in Medicine) is a standard format that enables medical professionals to view, store, and share medical images irrespective of their geographic location.
OpenSource:
https://medevel.com/10-open-source-dicom-viewers/
Aliza: https://www.aliza-dicom-viewer.com/download/download_alizams
ClearCanvas: https://clearcanvas.github.io/
MicroDicom (free for non-commercial use) https://www.microdicom.com/
looks good, requires Mac/Linux
This looks more promising, and actual web application