These packages are experimental and may work incorrectly or may not work at all.
In case of errors (crashes, incorrect rendering) please refer to issue trackers:
https://bugreports.qt-project.org/issues/?jql=project%20%3D%20QTWEBKIT%20ORDER%20BY%20key%20DESC
https://github.com/OtterBrowser/otter-browser/issues?labels=upstream+issue&page=1&state=closed
Preferred way to obtain binaries is to build own using Qt SDK 5.4.0 or later (5.5 is recommended), it can be obtained here:
http://www.qt.io/download-open-source/
More details can be found in INSTALL file in source package.
AppImage package requires GStreamer 1.4 or newer and OpenSSL 1.0 to be installed.
See wiki page for list of all available packages:
https://github.com/OtterBrowser/otter-browser/wiki/Packages