Open Access Text Book Publishing

I am wondering what other open access textbook publishing initiatives are around?

I am aware of Open Suny which describes itself as follows:

Open SUNY Textbooks is an open access textbook publishing initiative established by State University of New York libraries and supported by SUNY Innovative Instruction Technology Grants. This pilot initiative publishes high-quality, cost-effective course resources by engaging faculty as authors and peer-reviewers, and libraries as publishing service and infrastructure.