After some internal discussion and canvassing of the Open Educational Resources community, we’ve switched the license from Creative Commons Attribution-ShareAlike (CC-BY-SA) to Creative Commons Attribution (CC-BY). BY-SA requires that anyone is free to use & modify a work as long as the modified work is “shared alike,” i.e., under a compatible license. The idea is that if you use it, you have to let others use your improvements & modifications as well. This is a laudable goal, of course, and we hope anyone who does build upon the OLP will do so! But it does, e.g., require that everyone who builds their own version of a textbook on the basis of OLP to license it under CC-BY-SA. An instructor may not want to allow redistribution of their adopted text at all, for instance. So CC-BY-SA potentially restricts the usefulness of the project and inhibits uptake.
