Open textbooks are increasingly seen as a potential solution to some of the challenges with the traditional textbook publishing model.
For a textbook to be considered open, it must be licensed in a way that grants a baseline set of rights to users that are less restrictive than its standard copyright. A license or list of permissions must be clearly stated by the author.
Generally, the minimum baseline rights allow users at least the following:
Many authors also grant rights such as:
Some advocates believe that the baseline rights must be more extensive to be considered "open" (see Controversies).
Since open textbooks can be used at no cost and printed at the cost of production, the use of open textbooks would reduce the cost of education significantly.
Open textbooks are also seen by advocates as potential competition in the textbooks market. Nicole Allen of Make Textbooks Affordable told USA Today:
"The open textbooks that are out there serve as proof that it is possible to have a high-quality open textbook that is being used in classrooms. They might just be the thing that will change the textbook industry for the better."
More on textbook affordability.
Open textbooks are flexible in ways that traditional textbooks are not, which gives instructors more freedom to use them in the way that best meets their instructional needs.
One common frustration with traditional textbooks is the frequency of new editions, which force the instructor to modify the curriculum to the new book. Any open textbook can be used indefinitely, so instructors need only change editions when they think it is necessary.
Many open textbooks are licensed to allow modification. This means that instructors can add, remove or alter the content to better fit a course's needs.
Furthermore, the cost of textbooks can in some cases contribute to the quality of instruction when students are not able to purchase required materials.
The most common open licenses are:
Creative Commons 
GNU Free Documentation License 
Public Domain
Open textbook authors do not receive compensation for the use of their textbook. Some authors receive indirect compensation through the sale of printed copies, supplements or advertising, or are subsidized by institutions or grants.
Since it is the decision of the author to make a textbook open, authorship is voluntary.
A number of projects seek to develop, support and promote open textbooks.
