[m4rtink]

I think they do, just an old one as ESR AFAIK does not guarantee you stability of the internal APIS needed for embedding between ESR versions.

I think it's at least 45 ESR, as mentioned in release notes ~year ago: https://blog.jolla.com/hossa/

There is an issue tracking the Gecko update on the community discussion/bug reporting tool used for Sailfish OS: https://together.jolla.com/question/133621/update-gecko-in-t...

The source of the Sailfish OS browser lives here: https://github.com/sailfishos/sailfish-browser

(Even though Sailfish OS is sadly not fully open source, the browser is as are other core applications and frameworks.)