I think you are confused. Twitter had basic auth and they gave us transition period. xAuth is OAuth but doesn't require a web based interaction to authorize. W

I think you are confused. Twitter had basic auth and they gave us transition period. xAuth is OAuth but doesn't require a web based interaction to authorize. With xAuth, apps ask for a username and pass but get a token and only store the token (instead of storing the username and pass like with basic auth). This was created to help with UX of non-webapps like mobile and desktop. The first release of xAuth was Seesmic Look which was after basic auth was in the count to shutdown. xAuth is only given to apps that are approved by Twitter that prove that they are not a web service and need the improved UX. The issue is that these apps are usually clients that desktop and mobile and probably need DM access, but xAuth clients can't ask for DM access (they are only allowing that access to clients that web auth).