Perusall - a collaborative e-book reading tool -- overview presentation by creator Gary King
panOpen - a learning platform that "includes full courses, textbooks, video, tests, software and syllabuses. The panOpen platform lets faculty curate and customize peer-reviewed content for free, while students pay [a per course fee] to access the materials." (from EdCrunch)
hypothes.is - an interactive web annotation tool. Hypothes.is describes itself as "a conversation layer over the entire web that works everywhere, without needing implementation by any underlying site…Using annotation, we enable sentence-level note taking or critique on top of news, blogs, scientific articles, books, terms of service, ballot initiatives, legislation and more."