In 2007 the mission of the Arbor Center for Teaching expanded to include the publication of material underpinning the Arbor School curriculum. The aim has always been to employ teachers as authors, recording their own best practices for the benefit of future generations at Arbor and extending Arbor-grown materials to other progressive educators. Our first effort was Cambium, a quarterly journal that captures content from our K-8 classes. In 2008 we began work on the Arbor Algebra series; Senior math and humanities teacher Linus Rollman drafted Jousting Armadillos that summer and we gave it to the class of 2011 for field testing in September. In June of 2010 we held a writing retreat for five other faculty members to launch a series of curricular guides to the Thematic content of the Primary, Junior, and Intermediate grades, and Ben Cannon began work on a blueprint for the Senior Humanities program.