We describe the development of an online peer review module for the Moodle (http://moodle.org) course management system. We have designed the system to be quite flexible for many different methods of peer review. One important feature is a rubric authoring tool that allows instructors to create a table of criteria in an online form which students can use to submit their feedback. We discuss some peer review literature and then present some scenarios of use for this tool. We cover some design issues and how we addressed them and conclude with a discussion of evaluation and future work.