From: Jude Nelson [mailto:judecn@gmail.com]
Sent: Monday, March 23, 2015 3:50 PM
To: T.J. Duchene
Cc: dng@???
Subject: Re: [Dng] FW: Devuan commitments - will trade-off be applied?



Technically, Wayland is the protocol definition, not the implementation
(i.e. think X11 vs X.org). Weston is the reference implementation.



[T.J. ] Good point. I was using the term Wayland more or less generically.
Yes, I know, but thank you for the correction. Hopefully, it will be less
confusing.



While it is true that most of the Wayland/Weston developers are also X.org
developers (and most come from Linux), they are making all the right moves
to avoid lock-in to Linux or a particular Wayland implementation. For
example, while there are multiple Wayland implementations (i.e. a Wayland
window manager or widget toolkit is effectively a Wayland protocol
implementation), inconsistencies between an implementation and the
specification are treated as bugs in the implementation. As another
example, Wayland avoids relying on FreeDesktop technologies like dbus and
systemd.



[T.J. ] Also correct.



You may be interested to know that the Wayland protocol is not tied to a
particular rendering technology or paradigm. To use the OSI analogy,
Wayland lives in the presentation layer--it's concerned with helping
applications identify and interact with the host's output devices, input
devices, and pixel memory buffers (on both an individual level and by
groupings). The protocol itself is not concerned with users, sessions, or
GPU infrastructure, nor is it concerned with widget sets, windowing,
decorations, etc.


[T.J. ] Yes, I know.


While I am not commenting as to their ultimate aims, which OVERALL are
actually quite admirable and agnostic, it is still less than desirable that
a key technology: KMS IS part of the initial implementation, which in turn
becomes the "reference implementation" for all practical purposes. KMS as a
software is Linux specific. While there are equivalents out there, they are
certainly less developed. When I criticize Wayland, it is over concern that
Linux-isms have worked their way into the final version of the stack, making
it less portable to systems not using Linux KMS. I think you can agree that
that concern is not entirely unjustified, given that a number of supposedly
platform agnostic software projects have Linux peculiarities in their code
that make them difficult to port to other UNIXes.

I freely admit that until we see the final version of Wayland, it is hard
to judge if it is merely overcaution.

T.J.