A computer-based educational system for use by teacher and student users and including a server computer and at least one client computer having a display and user input device is disclosed. A lesson builder allows teachers to create customized lessons incorporating lesson material that includes text, audio, images, video and application programs into a lesson for delivery to the student user. Lesson material can be drawn from a variety of sources, including a lesson material data base, a database of existing lessons, and the Internet. Teachers can add interesting lesson material to the lesson material database for use by other teachers. Lesson material can be presented in a lesson directly or as a link, such that the student is presented with the material at the student's option. Students may access the Internet during execution of the lesson, and may collaborate with other students as well as the teacher. The system is typically accessed by teachers and students via Internet browser applications receiving web pages served from the server computer, which communicates with the client computer via an intranet or the Internet. The functionality of the system of the present invention can be realized using standard commercially available hardware and software.