Translations:Quick start guide - LimeSurvey 3.0+/16/en
From LimeSurvey Manual
Note: You can unsubscribe at any time by accessing your profile menu and un-ticking the LimeSurvey newsletter option from your mailing list, located under your community profile.
For a faster registration process, LimeSurvey allows each user to sign up via their own Twitter, Gmail or GitHub account. LimeSurvey will gather the basic information that is required from your selected source.