How to submit a folder with all of it structures and files?

I'd like to submit a folder by dragging and dropping it into someplace and it will automatically be saved to the server side (by keeping all of its original structure).

So my questions:

1) How to implement that? Which server-side (client-side) controls should we use?

2) If I submit a folder with all of the files (or sub folders). How to analyze them quickly?

3) This should be fully compatible with all of explorers such as IE, Chrome, Firefox.....