Comment by parul

You are right, @Wuliwong. Our learning paths ("tutorials" comprised of online courses, videos, blog posts etc) are free, and experts help curate them for the joy of sharing their knowledge and giving back to the community. We are working on paid online programs, where learners get 1-1 mentorship and greater engagement with experts and the student community. (ps: I am one of the founders of SlideRule)