select2/select2 ? reverse-engineered prompt

Build me a jQuery plugin that makes normal select boxes feel modern and easy to use.

I want people to be able to click a select field and search the options, choose one or many items, add new tags on the fly, and handle grouped options nicely. It should also work when the options come from a server, so as someone types it can load matching results with AJAX and keep loading more when they scroll to the bottom.

Please include a simple demo page showing a basic select, a multi select, tagging, remote search, grouped options, and custom looking results. Keep it usable as a normal select underneath so forms still work. Add a clean default style, a small docs page with setup examples, and enough tests to make sure the main behavior doesn’t break.

Use jQuery since this is meant to improve regular select boxes. Look up current docs online if you need to.