Wagtail is an open source content management system (CMS) written in Python and built on the Django web framework. It is aimed at development teams and editors who build bespoke websites. StreamField gives editors flexible control over page layouts, content can be delivered in a traditional or headless way, and multilingual publishing is available through Wagtail Localize. Wagtail is not a hosted service but software that you install yourself, for example with pip, on the infrastructure of your choice.
Wagtail began in 2014 at Torchbox, a digital agency in Bristol, England, which still sponsors the project and offers help with implementation and hosting. It has since grown into a community project with many contributors. The licence is BSD-3-Clause: free to use and modify, including in closed-source code. Because you host it yourself, you decide where the data sits, for example with a European hosting provider. The United Kingdom lies outside the EU; no US parent company is mentioned in the sources consulted.