X compression techniques (was Re: VNC server based on kdrive using damage extension?)

[Gian Filippo Pinzari]

Egbert Eich wrote:
> It will become interesting once one thinks about integrating this
> technology directly into the client lib/Xserver.

I don't agree with that. In theory you could build a web
server into the kernel (and somebody did that), in practice
layering has advantages. NX is designed to be on top of X,
as well as on top of other protocols like RDP and SMB.
Building some parts inside X (libs and server) can surely
offer performance advantages, but would also add a lot of
unrelated complexity. What X needs is to be streamlined.

We are not directly involved in X server development,
the same way as Apache developers are not usually involved
in Kernel. Anyway, when we need a particular fix or a slight
modification to X, we release the changes under the GPL.
For example we modified the Xwin X server to not rely on
Xlib for rootless operation. The code is there, if anybody
is interested.

> Other plans exist to reduce wire round trips however from all what
> I know about NX's solution it is doing a lot more - like persistent
> caching of pixmaps even between X sessions.

Any improvement in X server and libraries aimed at reducing
the number of round-trips or adding features like persistence
of sessions is not only welcome, but mandatory for evolution
of X technology. This will benefit all X applications, both
local and remote, and will make NX even more efficient.
Anyway X doesn't need persistence of bitmaps when running
in local-local conditions. Adding this and other features to
the core X is a bad idea, like making a web server in kernel.
Saying that NX is not of interest for X development, anyway,
is another story and I think people should look at it instead
of relying on second-hand reports.

> Kurt's email may have been written a little bit from a salesperson's 
> point of view

For what I know about Kurt, the mail has been written by
somebody who is used to fight people spreading misconcept-
ions.

/Gian Filippo.

P.S.: I had notice of some GNOME developers that want to host
a free NX server project on fd.o. I hope they will do that
soon. I'm tired of self-advertising our work.