LimeSurvey is a FREE open source survey application.
Lime Survey is similar to SurveyMonkey (which I use often and love) with the main difference being that it gives you unlimited number of surveys, unlimited number of questions per survey, and unlimited number of participants to a survey. With SurveyMonkey these things are all possible, but one must upgrade to a Pro account and pay monthly in order to have those options.
In addition LimeSurvey includes 20 different question types and supports over 50 different languages. Check out this fabulous free site to create surveys for your parents and students today!