Openly Available Sources Integrated Search (OASIS) is a search tool that aims to make the discovery of open content easier. OASIS currently searches open content from 115 different sources.

OER Commons offers a comprehensive infrastructure for curriculum experts and instructors at all levels to identify high-quality OER and collaborate around their adaptation, evaluation, and use to address the needs of teachers and learners.

Transform Higher Education and Student Learning: Open textbooks are licensed by authors and publishers to be freely used and adapted. Download, edit, and distribute them at no cost.

Find content you can share, use, and remix. Includes various types of media.

OER Commons offers a comprehensive infrastructure for curriculum experts and instructors at all levels to identify high-quality OER and collaborate around their adaptation, evaluation, and use to address the needs of teachers and learners.

The Public Domain Review is an online journal and not-for-profit project dedicated to the exploration of curious and compelling works from the history of art, literature, and ideas.

Saylor offers full courses online. Their texts and content may be useful in your own courses. This page showcases Saylor's Art History course.