Flat World Knowledge - free, online textbooks

About Flat World Knowledge : We preserve the best of the old - books by leading experts, rigorously reviewed and developed to the highest standards. Then we flip it all on its head. Our books are free online. We offer convenient, low-cost choices for students – softcovers for under $30, audio books and chapters, self-print options, and more. Our books are open for instructors to modify and make their own (for their own course - not for anybody else's). Our books are the hub of a social learning network where students learn from the book and each other. ...It’s this easy: search our catalog, request a print review copy or review our book online, complete an online adoption form, give a URL to your students, and download our supplements. Done. It really is that easy."