LimeSurvey
LimeSurvey is an open source survey application. LimeSurvey was formerly known as PHPSurveyor.
LimeSurvey enables surveys to be developed and responses to be collected and analyzed. LimeSurvey includes a wide range of built-in question types, and a range of flexible options. Surveys can include branching, different layouts and designs (using a templating system), and can provide basic statistical analysis of survey results. Surveys can be public, or can be strictly controlled through the use of unique tokens for each survey participant.
-LimeSurvey developer