One example of this is Boundless. This compiles free e-textbooks from open educational resources. Boundless helps you replace your standard course textbook with an e-book of open content including texts, images, film, sound and animation. The resulting e-book can be accessed by laptop, tablet or mobile and is instantly available to all students. It can be used as a supplement to a printed course book or can simply replace the printed version. It's all free, at least in its present beta version but there are of course premium services such as SmartNotes.
As more and more solutions like this emerge the role of the textbook publishers becomes very insecure. The arguments for free online e-books are irresistible for students and highly attractive for cash-strapped educational authorities, many of whom are looking at the open textbook sector already. The key factor in this competition is quality assurance. How trustworthy is the material retrieved by services like Boundless? Is it equally well selected as the equivalent material in the printed textbook? The printed textbook has been written as a logical progression with clear developed themes whereas the digital version is a mix of completely independent modules. Quality in open e-books depends on effective tagging including parameters for subject matter, objectives, learning outcomes, age group, level and so on. As the meta data improves and resources are produced with more thought for reuse then solutions such as Boundless will become increasingly attractive.
Definitely worth investigating further.
Read a short review of Boundless on Edudemic: The Future Of Textbooks Is Free … And It’s Now Available.