Here is a HTML5-Gtk Player, which I released together with PostX 0.4.2. It plays Youtube and HTML5 with Python. Note. The dependencies listed below might be different depending upon your system version or Linux distribution.

#HTML-GTK PLAYER Copyright (c) 2017 JJ Posti <techtimejourney.net>
#This program comes with ABSOLUTELY NO WARRANTY;
#for details see: http://www.gnu.org/copyleft/gpl.html.
#This is free software, and you are welcome to redistribute it under
#GPL Version 2, June 1991″)

4th of March 2018:

HTML-GTK Player v.4 is added This release fixes some bugs.

11th of September 2017:

HTML-GTK Player v.3 is added. This release fixes HTML5 rendering issues on Youtube.

2nd of July 2017:

Get Html-Gtk-Player v.2 from here. Functionality remains the same – Vimeo support is added.

Dependencies:

python-webkit #Edit. This package is something that is very unlikely needed.
python3-gi
python-gi
python
python3
gir1.2-gst-plugins-base-1.0

gir1.2-webkit-3.0

gstreamer1.0-plugins-bad
gstreamer1.0-plugins-base
gstreamer1.0-plugins-good
gstreamer1.0-libav

Html5 Player start screen.

Htm5 Player in Youtube.

The future of this player’s back-end is in C++

It seems that Debian is about to remove python-webkit from the next stable branch – since the package , apparently, has no maintainer. The good news is that I have already coded a new player back-end with C++. The front-end will be python QT5. The new player will be released as soon as I complete full stability testing. In the mean time you can continue using this player. PostX users will receive an automatic update once the new player arrives.

Edit. Python-webkit removal should not be an issue. Regardless of Python the future of this player is still happening in C++ – since the upcoming new code will likely perform very well on a future Debian base(Stretch)

Download Html-Gtk-Player (as a zip) <– older version

To run the program: open terminal and do: python html5.py

If you need to make the file executable: chmod +x html5.py