To build:
$ Tools/Scripts/update-webkitwpe-libs
$ Tools/Scripts/build-webkit --wpe --threaded-compositor
To run (assuming you're executing under a Wayland compositor):
$ Tools/Scripts/run-wpe
$ Tools/Scripts/run-wpe http://www.bouncyballs.org
To run under a specific Weston instance:
$ weston --socket=wpe-test
$ WAYLAND_DISPLAY=wpe-test Tools/Scripts/run-wpe