We're seriously evaluating the possibility of open-sourcing the product, following the example of ie. Ghost. It's pretty clear to me that it's the only way we can 100% guarantee to our customers a product that's here to stay.

Nevertheless, static websites are extremely open by-design. If you're no longer interested in using DatoCMS for whatever reason, you can simply export all the content and go back editing your Markdown files manually or with some other tool.