• The IMS Global organization has a tool to compare up to three Open Badge platforms:https://www.imsglobal.org/cc/statuschart/openbadges
• Badge Alliance also has a list of Open Badge platforms: http://www.badgealliance.org/badge-issuing-platforms/

• College of the Canyons did its own badge platform review last year, which was documented by SynEd:https://syned.org/2018/10/05/summary-of-digital-badge-provider-comparison-at-college-of-the-canyons/
• The Colorado Community College System put together a comprehensive white paper about its use of badges: https://www.cccs.edu/wp-content/uploads/documents/CCCS-Digital-Badging-Taskforce-Whitepaper-11.12.14.pdf

We are exploring the very same topic.  We have been using Credly for the past year or so to give badges to faculty who complete courses in a 3 course series we developed for effective online teaching.

That said, we are a Canvas school and, as we explore our own pilot program, are looking at Badgr’s badging solution (which is free to use, at least for Canvas, maybe all though?) as well as their Pathway’s solution for stacking badges and providing a view of that badge path for participants.

It’s is all very early stage but those are the two platforms and vendors we have focused our time currently.