Question

Is there any way to stop # from appearing inside the address bar when using Backbone routing, pushState or not?

Answer 1

Current versions of IE do not support pushState. (It appears in the IE10 previews).

Your options are either to drop down to normal (non-Ajax) links / form submissions / etc, or use the hashbang hack.

I don’t know backbone well enough to say for sure, but the following might be sufficient to fallback to normal routing:

if (window.history && window.history.pushState) {
    Backbone.history.start({pushState: true});
}