Today marks the beginning of the second half of the month, and with it, the Ides of March are safely behind us. What else is behind us: the beta launches of several Flexbooks, aka the CK-12 Foundation‘s version of open source textbooks. The most notable Flexbook is the one we mentioned last fall—notable because of…

We’ve all heard of the textbook. Some of us have read one or two in school. Others of us have stared blankly at pages filled with outdated information. Still, others of us are more resourceful and have used the bulky things to prop up rickety ends of tables. But all of us have had to…