INSTALLATION: 1. Upload files 2. Import XML 3. Create twitter application http://dev.twitter.com/apps and put its Consumer Key and Consumer Secret to addon's options. FEATURES: 1. Registration of a new account via Twitter 2. Association of an old account with Twitter account NOTES: 1. If user tries to uses several providers same time he can get problems http://xenforo.com/community/threads/user_id-key-within-xf_user_external_auth.24776/ 2. Complete removal of the addon will leave twitter users without password.