Google Chrome desktop browser and Chrome for Android include now support for WebRTC (Web Real Time Communications), an emerging web standard that helps  real-time audio and video capabilities to their web applications without the need for plug-ins or proprietary codecs.
There are various  apps has capabilities like voice calling, audio & video conferencing, video broadcasting, screencasting and screen sharing in the browser via simple JavaScript without requiring plugins.

Some of  web apps are like http://same.io,http://talky.io http://appear.in to Video /Voice chat Screen sharing without  installation or download anything. Only you require is the latest Chrome browser.

There’s a little setting in Chrome that you need to enable . Type chrome://flags in your Chrome’s address bar, find the setting that says “Enable screen capture support in getUserMedia()”, click the Enable button and restart your Chrome browser.

Here is some good news for Microsoft account user, Microsoft will integrate Skype into its Outlook.com email service. With this implementation they will be able to indulge in voice and video communication, in addition to the conventional text communication
This means that people can check their e-mails and talk about the contents simultaneously. In case you forgot, Outlook.com is the successor of the Hotmail.com email service

Microsoft  in a blog post that a preview version of Skype for Outlook.com would be rolled out starting right now. Although this version will first be available to Outlook.com users in the United Kingdom
Microsoft says that users of other countries would get the preview version soon. Indian users will have to wait to benefit from the service integration


According to Microsoft to enable Skype for Outlook.com email, one has to download a plug-in for their web-browser - recent versions of Chrome, Firefox and IE are supported.Thereafter, users can use their MS account to connect Skype to their Outlook.com Inbox.

To understand how really it will work please visit this video

Close on the heels of Google launching its latest social networking venture Google+, Facebook is addiing video chat to its pages. The feature powered by the Internet phone service Skype will allow Facebook's over 750 million users to make video calls on the site. Facebook has also redesigned its chat feature, so that the people whom a user messages the most, show up first.
Here's all you should know about the all-new Facebook video chat: how it works, setting up, blocking people, who all can call you and much more.
To get started you need a webcam and microphones. If you and your friend both have webcams and microphones set up, you will be able to see and hear each other in real time.
In case, you call a friend who doesn’t have a webcam, she will be able to see and hear you, but you'll only be able to hear her.
You are required to complete the set-up the first time you try to call a friend, or the first time a friend tries to call you. Now, to get started, just click on the video icon at the top of your chat window.
To start set up, just click the "Set Up" button and follow the instructions given for your browser.
Now just go to the profile of the person you wish to chat with and click the "Call" button in the top right corner. If the set-up is done, the call should connect automatically. In case it doesn’t, call again by clicking the video icon at the top of your chat window.

Once the call is answered, you may have to wait a moment for your call to connect before the video call begins. As the person you call too will have to complete the set up.