"An OpenCourseWare (OCW) is a free and open digital publication of high quality college and university‐level educational materials. These materials are organized as courses, and often include course planning materials and evaluation tools as well as thematic content. OpenCourseWare are free and openly licensed, accessible to anyone, anytime via the internet."
defined by Open Educational Consortium
Astronomy
Biology
Chemistry
Computer Science and Information Technology
Free Online Computer Science Course Featuring Harvard Faculty
Open Access Books - Computer and Information Science | InTechOpen
Construction Management
Engineering Chemical
Engineering Civil
Engineering: General Resources
DOAB: Directory of Open Access Books (Technology and Engineering)
Engineering: Mechanical
General Science
Health Sciences
Mathematics and Statistics
eBook and Texts : Internet Archive (search under Mathematics)
Electronic Journals Library (Mathematics) (green indicates OA)
Nursing
Physics