Zoomerang is an online polling & surveying site. The basic, aka free, account allows you to create an unlimited number of surveys & polls, each having up to 12 questions, and 100 responses. Results can be viewed in real-time. This is ideal for surveying small population like a class or grade level in a school, or even as a virtual testing/quizzing tool!
This is a great tool to prepare quizzes, or create practice exercises to help students prepare for exams. It has six applications. Allows you to make interactive multiple-choice, short-answer, jumbled-sentence, crossword, matching/ordering and gap-fill exercises for the Web. It is not an open source.
Question Tools is a program with a server client that allows the generation of interactive testing. It takes a certain amount of technical knowledge to set up the server, but test generation is easy.