Waterfox was one of the first widely distributed 64-Bit browsers on
the Web and quickly gained a loyal following. At one time, Waterfox
had one thing in mind - speed. But now Waterfox also attempts to be an
ethical, user-oriented browser.

Features:

    Disabled Encrypted Media Extensions (EME)
    Disabled Web Runtime (deprecated as of 2015)
    Removed Pocket
    Removed Telemetry
    Removed data collection
    Removed startup profiling
    Allow running of all 64-Bit NPAPI plugins
    Allow running of unsigned extensions
    Removal of Sponsored Tiles on New Tab Page
    Addition of Duplicate Tab option
    Locale selector in about:preferences > General

Waterfox is only available for the x86-64 architecture.

This SlackBuild just repackages the binary package provided by the project.
It doesn't attempt to build the browser from source.