LimeSurvey

A survey platform for building questionnaires, distributing them, and collecting and analysing the responses. It offers many question types, templates, answer piping, logic conditions, quotas, and token based access so each respondent sees a tailored set of questions.

Researchers use it for academic studies, while HR and marketing teams run feedback campaigns, satisfaction surveys, and event evaluations.

Hosting it yourself keeps participant responses, which often contain sensitive data, on equipment you control, with no per-respondent or per-seat price, and a database dump for dependable backups.