568412 Chat/Messenger/Video/Audio/FileShare using HTML5/Jquery/CSS

Hello all, I'm interested to have a Chat/Messenger/Video/Audio/FileShare/GroupChat/ListSharing application that works on windows desktop, ios, android, windows phone, mac. Please send details of how you would implement this and we can proceed. Would want to be able to login with IDs from facebook, OpenID, google, and just other reusable single-sign logins. Should receive notifications. Should be able to share checklists like a shopping list. And share calendar dates. Prefer microsoft-centric server-side implementation, not php/java. Maybe PhoneGap would be used to package the app.