Internet Mathematics Assessment System

IMathAS is a free, open source web-based math assessment tool for delivery and automatic grading of online math homework and tests. Questions are algorithmically generated and numerical and math expression answers can be computer graded. Beyond that, IMathAS includes learning management tools, including posting of announcements, text files, and attachments, as well as discussion forums and a full gradebook. In postings and assessments, IMathAS allows accurate display of math and graphs, with simple calculator-style math entry and point-and-click graph creation.

See http://www.imathas.com for more information.