"ChemWiki" is a free online alternative to costly textbooks. Since March 2014, the wiki, created by UC Davis chemistry professor Delmar Larsen, has saved students over $1.5 million when used as an assigned text in courses at 10 different institutions, including UC Davis. The site attracts over 5.5 million visitors a month, making it the most visited domain among UC Davis’ websites.

An undergraduate general chemistry textbook can cost hundreds of dollars. Yet the material in such textbooks is well established, in some cases for decades, Larsen notes. 

Larsen started ChemWiki with entries written by students and vetted by volunteers. Much of the content is now gathered, with permission, from course notes, professors' websites and other locations across the Internet.

A recent study of UC Davis chemistry students using ChemWiki as their principal reference versus a standard textbook found no essential difference in learning, Larsen said.

Larsen leads a consortium including UC Davis, Sonoma State University, Diablo Valley College, Hope College (Michigan), Howard University (Washington, D.C.), College of Saint Benedict/Saint John's University (Minnesota), and the University of Arkansas, Little Rock, to expand ChemWiki and an associated network of other scientific wikis in chemistry, physics, biology, math and other subjects. The project receives funding from the National Science Foundation.