This document discusses open source textbooks through the ConneXions platform. Open source means publicly accessible materials that can be copied, shared and remixed for free. ConneXions provides open source textbooks through its website, where users can search subjects, interact with materials, download PDFs and sometimes other formats. Some textbooks can also be printed or bought at a lower cost. The document addresses concerns about accuracy but notes that "lenses" review content for quality, and many eyes increase accuracy as with Wikipedia. It encourages exploring the open textbooks by signing up at CNX.org.