For the HTML inputs like radio and combo box, it is possible along the way. Ashley will confirm or deny this (at worse I believe the third part dev community will tackle this someday if it is not taken care of in the meantime).
Nothing prevents you from making your own components through events (for radio button for example, it is nothing more than a 2 frames sprite + a text object eventualy).
For ini/files writing/reading, you already have the webstorage object, or even the AJAX object that would let you interface saving and retrieval to/from a database.
Finally popup windows are already doable too with the browser object.
You can also make your way with several layouts/layers and have multiple "windows" app in a single canvas.