I believe the decision to fall back on prefixed implementions of indexedDB should be left to the user of the library. In this case it could be suggested that they do the renaming of the prefixed before loading any of the other scripts:
var indexedDB = window.indexedDB || window.webkitIndexedDB || window.mozIndexedDB || window.msIndexedDB ;
var IDBTransaction = window.IDBTransaction || window.webkitIDBTransaction || { READ_WRITE: "readwrite" }; // No prefix in moz
var IDBKeyRange = window.IDBKeyRange || window.webkitIDBKeyRange ; // No prefix in moz
window.IDBCursor = window.IDBCursor || window.webkitIDBCursor || window.mozIDBCursor || window.msIDBCursor ;
// --> load backbone-indexeddb here
I am sending this in as a way to discuss this.
I believe the decision to fall back on prefixed implementions of indexedDB should be left to the user of the library. In this case it could be suggested that they do the renaming of the prefixed before loading any of the other scripts:
Browser support: http://caniuse.com/indexeddb