LimeSurvey (Create online surveys instantly)

LimeSurvey basically contains everything you need for doing nearly every survey with grace.

LimeSurvey currently offers:
Unlimited number of surveys at the same time
Unlimited number of questions in a survey (only limited by your database)
Unlimited number of participants to a survey
Multi-Lingual Surveys
User-Management
20 different question types with more to come
WYSIWYG HTML Editor
Quotas Management
Integration of pictures and movies into a survey
Creation of a printable survey version
Ability to set conditions for questions depending on earlier answers (branching the survey)
Re-usable editable answer sets
Ready-made importable questions
Assessment surveys
Anonymous and Not-Anonymous survey
Open and closed group of participant surveys
Optional public registration for surveys
Sending of invitations, reminders and tokens by email
Option for participants to buffer answers to continue survey at a later time
Cookie or session based surveys
Template editor for creating your own page layout
Extended and user-friendly administration interface
Back-office data entry possibility
Survey expiry dates for automation
Enhanced import and export functions to text, CSV, PDF, SPSS, queXML and MS Excel format
Basic statistical and graphical analysis with export facility
Screen Reader Accessiblity
W3C compliance

Supporting more than 46 different languages in frontend and backend:
Basque
Bosnian
Bulgarian
Chinese (Simplified)
Chinese (Traditional)
Chinese (Taiwan)
Croatian
Czech
Danish
Dutch
English
French
Galician
German
Greek
Hebrew
Hungarian
Italian
Japanese
Latvian

Lithuanian
Macedonian
Norwegian
Polish
Portuguese
Romanian
Russian
Serbian
Slovene
Spanish
Thai
Turkish
Swedish
Vietnamese
Welsh

....more to come