You need libwebkit2gtk-4.0-dev, libseed (from git) with patch to use libwebkit2gtk-4.0 and javascriptcoregtk-4.0.
The extension is still a bare Makefile inside the src directory, I'll update it as soon as I really put my faith into this seed-way or the custom node-like JavaScriptCore-way.
--version
Get current maleo version number.
--debug
MIT