Bootstrap Modals for alert() and confirm(). Requires Bootstrap 3.0+ and jQuery. Demo
bower install bootstrap-simple-prompts
alert(message, [title])
confirm(message, [title], callback)
You can access the browser-defined implementation via:
alert.original(message)
confirm.original(message, callback)
Originally, this was a fork of sairam's bootstrap-prompts, but after significant departure, I rewrote it.