LimeSurvey is a survey software to create online surveys. Features open/closed surveys, branching, participant administration, quotas, WYSIWYG HTML editor, email invitations & reminders, assessments, basic statistics and more.
A script written in pure PHP that can easily generate dynamic surveys based off of included template CSV (comma separated value) files. Setting up the script is as simple as editing the template file and transferring the directory to a server.
phpESS-ng (The php Email Survey System Next Generation) is a E-Mail survey tool written in php. It is a fork of the phpEES (The php Email Evaluation System) written by Johannes Kern (http://www.johannes-kern.de/), Daniel Flaschka and Michael Prell.
PHP Interview System is a easy-to-use research system to build complex survey(s), interview(s) and poll(s). The interview can be dynamic (interactive) flow. Collect and react on input. Export data for analysis.
An Open Source, web based mail survey tracking system. queXM has sample management, uses AAPOR outcomes, can implement the Total Design Method (Dillman), generates postal manifests, and assists with questionnaire form archiving and tracking.