[webkit-dev] Proposal: upstream the WPE port

[zan at falconsigh.net]

Hi,

the WebKit team at Igalia would like to propose upstreaming the WPE port
of WebKit, taking on the duty to maintain it alongside the GTK+ port.

The WPE port started in 2014 as the 'WebKit for Wayland' project inside
Igalia [1].  The port was derived from the GTK+ port, but avoided
dependency on any GUI toolkit.  It relied on the Wayland display
protocol for on-screen presentation.  That dependency was later dropped
in favor of using generic interfaces to adapt to different
platform-specific presentation systems.  This allows any vendor to
simply provide the necessary backend implementations that are tailored
to their platform.

The port is intended to be the Web platform engine of choice for
embedded Linux systems.  Since late 2014 Igalia has been sponsored by
Metrological to further develop the WPE port, targeting primarily
various set-top box platforms.  Miguel Gomez blogged about this effort
back in December [2].  The port can also address other embedded use
cases, for instance in-vehicle infotainment or digital signage.

The GTK+ and WPE ports mostly have the same dependencies except for the
GTK+ toolkit library.  That enables the two ports to already share a lot
of code.  The biggest difference between the two is that the WPE port
exposes the WebKit2 C API, while the GTK+ port exposes a GObject-based
API.  Apart from that, the maintainers' plan is to further align the two
ports as much as possible, ideally simply stacking the GTK+ port on top
of WPE, with only a few additional tweaks for GTK+ integration.  This
would lessen the maintenance burden for both ports and the project as a
whole.

The WebKit team at Igalia thinks this port is on stable footing and has
solid prospects for the future.  That's why we'd like to join the
upstream community and continue our work there.

The patch with the port changes is in bug #171110 [3].  We have existing
x86_64 buildbot configurations [4] that we would have to port over to
the webkit.org build master.  We're planning further builder and tester
configurations for ARM architectures in the future.  Layout test
baselines would be landed separately.  (Those too would be subject to
alignment with the GTK+ port.)

We're happy to address any questions or considerations.

Regards,
Zan

[1]
https://lists.webkit.org/pipermail/webkit-dev/2014-December/027087.html
[2]
https://blogs.igalia.com/magomez/2016/12/19/wpe-web-platform-for-embedded/
[3] https://bugs.webkit.org/show_bug.cgi?id=171110
[4] https://build-webkit.igalia.com/waterfall?category=WPE