Per a discussion with Christian Heilmann, I've put together a little doc outlining the current IndexedDB issues in IE 10-11 and Edge.
The biggest issue with IE's implementation is the lack of multiEntry
, complex keys, or compound keypaths. Kyaw Tun (creator of YDN-DB) has grumbled a lot about this, and David Fahlander (Dexie.js creator) has written a heroic polyfill called IEGap that adds the missing behavior. (Although per David, it passes the W3C tests but not all the Dexie tests due to some tricky edge cases.)