All books are stored as git repositories so you get branching, history, etc ... out of the box.<p>We have great GitHub integration because it&#x27;s the main Git host out there, we store git repos too.<p>If we shutdown, our toolchain and book format is already open source (<a href="https:&#x2F;&#x2F;github.com&#x2F;GitbookIO&#x2F;gitbook" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;GitbookIO&#x2F;gitbook</a>), so no matter what you&#x27;ll always be able to use that to build your book locally. Secondly our Desktop Editor (<a href="https:&#x2F;&#x2F;www.gitbook.com&#x2F;editor" rel="nofollow">https:&#x2F;&#x2F;www.gitbook.com&#x2F;editor</a>) works offline so you could even continue to use that. And well since your book is a git repo, you can have a local copy, a copy on GitHub or any other git server of your choice. So I think you should be good :)<p>We don&#x27;t believe in vendor lock, we&#x27;re big supporters of open-source and we want users to use our tools and platform not because they&#x27;re obliged to, but simply because it&#x27;s the best workflow&#x2F;product for them.<p>Does that make sense ?