How to make it possible to edit/save MS Office documents directly on the site (as in Sharepoint)?

Question

ASP.NET

Hello!
MS Office can save, open, edit and save documents again not only on a local or network drive, but also in sharepoint, SkyDrive and some "Other sites" (this is an item in the save menu).
I assume that you can implement some methods on your site so that Word can open documents in edit mode from my site and save them there directly, as is done in sharepoint.
The question is how to make such support on your own site?