I am a developer a large social network.
Does the protocol OAuth without browser? I plan to write desktop and mobile applications that can not use your browser to get access_token. It worries me step for get Access_token, I can not understand how to implement it.
Give examples of code if possible ...
No, at least using the common OAuth flow (also called 3-legged).
You need to open a browser so the user can grant your app access to the protected resources.
You could use the 2-legged OAuth variation, but it's poorly documented and supported.
This has been asked before see http://stackoverflow.com/questions/1934187/oauth-secrets-in-mobile-apps