The webruntime module can be used to launch applications based on HTML/JS/CSS. This can be a browser or a runtime that looks like a desktop app, such as XUL (based on Firefox) or NW.js.
Webruntime is pure Python and requires Python 3.4+. It's only dependency is dialite.
pip install webruntime
>>> from webruntime import launch
>>> rt = launch('http://xkcd.com', 'app')
...
>>> rt.close()The code of Webruntime is distributed under the terms of the liberal 2-clause BSD license. See LICENSE for details.