Offers an online homework delivery system . Teachers can create assignments from a database of textbook questions, or write and customize their own exercises. Web Assign collects, grades, and records assignments instantly.
You have complete control over the homework your students receive, including due date, content, feedback, and question formats.
Service is free for teachers. Students pay about $10.50 per year.

The Quest Learning & Assessment System
Uses an extensive knowledge bank of over 60,000 questions and answers covering all sciences.
Quest makes it easy for instructors to create assignments by drawing from an extensive list of pre-existing questions. Each question has many variations to ensure students come up with their own unique answers. Quest’s automatic grading feature frees up more time for instructors so they can focus on teaching.