Earlier quoted context omitted.
Have you tried Sciter?
I do not really understand the lisence of this. In the repo it says its open source but on the website they ask for money?
But Sciter Engine itself (https://sciter.com) is not OS - its sources are available to customers only. I tried to make it Open Source ( https://www.kickstarter.com/projects/c-smile/open-source-sci... ) but not too much interest for that.