MIT’s BLOSSOMS program offers over 50 free math and science videos online, as well as a library of links to resources for STEM teachers in biology, engineering, math, physics, and science. The videos, all freely available for online viewing or downloading, are aimed to be used by high-school teachers in classrooms, enhancing classroom teaching:  They serve as a guest lecturer in the classroom and contain frequent pauses for classroom discussion and exercises led by the classroom teacher.  Each video comes with downloadable handouts and discussion guides and links to related resources.  Students may also find these videos useful for viewing at home.  The initial videos were made by MIT faculty and educators in Jordan and Pakistan, and new videos are being added by educators from around the world. (Thanks to Mass Science Fair for pointing this out.)