Do you have a project in mind for an open textbook or other open educational resources? The Rebus Community is inviting new projects for its beta rollout of its new platform for project organization, recruiting of collaborators, and more. Particularly looking for projects from outside of N. America and that include marginalized voices. I have a project w/Rebus and they're great!
See here for more info and how to apply: https://about.rebus.community/2018/04/rebus-community-projects-beta-invitation/
@chendricks Nowoczesna Polska is doing a lot in Poland https://nowoczesnapolska.org.pl (although they moved on from the textbooks towards source material and more specific issues like media education).
They have built some of their platforms already as they have been doing this for many years now, but it might be interesting to check them out.
@somenxavier The value is partly in having a platform that can help you organize your tasks and invite people to participate in various ways. This is most useful if you want to involve others in the project, including to do peer reviews if not to write part of the content.