Textbooks are resources for learning that provide the structure, content, assessments, and teacher guidance for an entire course. Technology can provide a far better resource that provides the same functions, but takes full advantage of computers. This resource would be much more than text on a screen. It would use the best technology; it would be student oriented, utilizing highly interactive, vivid, inquiry-based activities embedded in intelligent electronic lessons. It would track student use and provide feedback to teachers, giving detailed analysis of student progress. It would be research-based, tied to standards, well tested--and free. Educators need a similar paradigm for creating outstanding educational materials: a curriculum collaboratively developed and shared instead of created by publishers or researchers. How can this be developed? Using the current top-down textbook development cycle, a large, skilled team would be needed: classroom savvy content experts, software wizards, assessment statisticians, curriculum designers, and university researchers. Developing comprehensive electronic materials for even a single course would be time consuming and expensive. And after several years and tens of millions of dollars, a team might produce a great design, but it might be too advanced or unfamiliar for most teachers to use. Envision a completely different, bottom-up development strategy: creating materials collaboratively through a community of educators who share knowledge, critique each other, and shepherd the evolution of a cluster of good materials. The result would not be a single, inflexible textbook handed down from on high, but a collection of malleable resources. This strategy is ambitious, but not impossible. The traditional encyclopedia is also expensive and time-consuming to create. But Wikipedia broke the traditional development mold. It has mobilized an international community of volunteers to generate an encyclopedia that has over 11 million articles in 265 languages, used by 275 million people a month. It is far larger than any text-based encyclopedia, easier to use, continually evolving, up to date, and free. Its sophisticated quality assurance system keeps most junk and errors out. Educators need a similar paradigm for creating outstanding educational materials. In this new paradigm, an instructor who creates an activity could submit it online and have it reviewed. Another can adapt the activity or materials for his own students. The result would be community-generated materials that are far more practical than any text. The collection could be almost completely self-supporting, with users generating new materials and serving as reviewers and promoters.