Khan Academy offers free microlectures on topics that cover math, science, economics, finance, and the humanities.

MERLOT is a curated collection of free and open online teaching, learning, and faculty development services.

MIT OpenCourseWare offers educational materials from MIT's undergraduate and graduate-level courses.

Open Course Library provides a collection of high quality, free-to-use courses that you can download and use for teaching.

EdX offers free online courses and classes. Find the latest MOOC from the world's best universities including MIT, Harvard, Berkeley, UT and others.

OER Commons is an online library that allows teachers to search for open educational resources (OER) and other freely available instructional materials.

CK-12 is a non-profit organization that creates and aggregates high quality, STEM content. The library includes over 5,000 math and science concepts and FlexBooks with multiple modalities for all learning types including: videos, images, reading, simulations, real world applications, activities, flashcards, study guides, assessments and more.

Connexions offers free educational material presented in small modules that can be organized as courses, books, reports, or other academic assignments.

EDSITEment provides collections of K-12 resources and lesson plans in the Humanities.

HippoCampus.org is a free academic web site that provides multimedia content--videos, animations, and simulations--on general education subjects in middle and secondary grades.

PBS LearningMEdia offers more than 100,000 digital resources available to PreK-12 educators. The resources provide research-based, classroom-ready digital learning experiences to engage students in exploring curriculum concepts that align with national learning standards.

NCLOR collects documents, audio/video clips, simulations, learning modules, assessments, and more – virtually any type of learning resource that can be digitized and processed. Teachers from around the state can then search NCLOR, find materials appropriate to the classes they are teaching, and use them as is or modify them to suit their needs.