Virtual laboratories enhance learning experience by providing a student with a supplement to the physical lab. Such laboratories allow students to perform excercises as in an actual lab and to gather data for preparing lab reports. To increase students' engagement and interest, they are allowed to take wrong directions and, and then backtrack to correctly perform the excercise. We developed a software framework for rapid development of interactive Web-based virtual laboratories. The framework was used to develop several introductory biology laboratories and the labs were used in actual classroom instruction.