Over the past two years, more than 200 people have written multiple choice questions and other assessment exercises as part of Software Carpentry instructor training. Many of these are very good, some are excellent, and they all deserve a second look to see whether they should be integrated into our lessons.
I have therefore pulled all the training course posts tagged "Assessment" or "MCQ" into a temporary GitHub pages site (the repository is here). If you are looking for a way to make a contribution to our material, recycling one of these would be a great way to do it (whether you're the original author or not). Please see our lessons page for the URLs of our GitHub repos—we look forward to your pull requests.