Testmaker is an application written in PHP for creating questionnaires that can be administered online. Provides multiple response formats (likert, single selection, multiple choice, open, etc.) and methods to store the results. The documentation is available at: http://jharo.net/dokuwiki/testmaker (spanish)
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.