Polls & Quizzes Software: Recommendations?

I have a series of database-driven websites powered by PHP and MySQL. They’re basically a multi-site CMS I created myself.

I’d like to install a series of polls and quizzes. I spent some time researching the topic a couple years ago, and there were lots of poll/quiz apps, but I never found one that really worked for me. The best ones, of course, were commercial - not really practical as my sites aren’t making much money from advertising yet.

I just checked out PollDaddy and PollSnack, and they look pretty good, but you have to pay an annual fee before you can really customize them. EastTestMaker looks interesting and is a lot cheaper. I wondered if there’s any comparable freeware or scripts that you could recommend.

It would be nice to have something linked to a database that would allow users to keep track of the polls and quizzes they’ve taken, their scores, etc. It would also be nice to have the ability to offer not just answers but explanatory text. For example: “You answered Sam Badger. That’s a good guess, but he wasn’t really a dictator.” (And that incorrect answer might be linked to an article about Sam Badger or dictators.)

One stumbling block is questions that require users to type in an answer. I suspect that might not even work without some way to allow for misspellings - for example, imagine if someone typed in “New Zeeland” rather than “New Zealand.” But if that’s too complex, I can simply avoid those types of questions.

Anyway, I just wondered if there are any particularly good software programs, apps or plugins that you’d recommend. I assume PHP would be the standard language, but I can also use jQuery. One of the commercial polls I mentioned above appears to use AJAX.

Thanks.

Perhaps you could try here: GitHub repositories matching quiz

One stumbling block is questions that require users to type in an answer. I suspect that might not even work without some way to allow for misspellings - for example, imagine if someone typed in “New Zeeland” rather than “New Zealand.” But if that’s too complex, I can simply avoid those types of questions.
I think the conventional solution is to use multiple choice rather than having any typing involved.

Yes, most forms of this type that I’ve seen use radios, checkboxes or selects, with only a limited number of (if any) inputs for user supplied text. (i.e. for “other” or comments)