[GRLUG] Thinking of app servers

[Michael Mol]

On Wed, Mar 3, 2010 at 2:43 PM, Adam Tauno Williams
<awilliam at whitemice.org> wrote:
> On Wed, 2010-03-03 at 14:20 -0500, Ben DeMott wrote:
>> I would love to make this work on my Mac... more than just 1
>> application at a time though.
>> So if you are using Gnome how do you start a remote Gnome Session /
>> Connect to a remote X Server with Gnome?
>> I've heard plenty of people say "Well you should be able to just do
>> this", but I've never actually seen it working.
>
> AS far as kicking up the required components via D-Bus it does "just
> work".
>
> I'll double check but I'm pretty sure I've setup nothing out of the
> ordinary.
>
>> I have seen it working with XNest but thats not a true remote session
>> -> but I digress.
>> Maybe the supplied window manager that comes with X does this more
>> gracefully? TWM or whatever?
>
> ?? I still don't get this.  GNOME/KDE are *NOT* window managers.  The
> Window Manager is nothing but a Window Manager.  [Although many people
> do seem to confuse Desktop-Environment & Window Manager].  The Window
> Manager is a client [which which is the "server" in X speak] component -
> it runs on your local display.

He's probably confused as to how X11 is laid out.

At the simplest level, you have an X server and multiple X clients.
The X server manages an abstraction from the hardware, and the x
clients are your applications.

One X client might be Firefox.  Another might be an xterm instance.  A
third might be your window manager. An X Window Manager is an X11
client that specializes in managing positioning the windows of other
X11 clients on the screen.  It will typically also draw window
decorations like the title bar, minimize/maximize/close, and the
draggable resizing borders.

GNOME and KDE aren't an X client, nor is it a window manager. Instead,
they're *collections* of X clients.  One of those clients may be a
window manager. Another may be the GNOME panel, where you drop applets
like your clock, menu and launchers. Another might be some of the
standard GNOME programs like gnome-calculator. (KDE has its own set.)
GNOME defaults to using a window manager, but I don't know what that
is right now. It used to be metacity, and before that I think it was
enlightenment. I don't remember clearly.

X's power lies in that an X server and X client don't need to reside
on the same machine. The control protocol works just as well over a
TCP/IP socket as over a UNIX domain socket. In fact, it's agnostic
enough that SSH can trivially provide its own transport mechanism.

Getting back to what GNOME and KDE are...you could think of them as an
X11 analog to Linux distributions, if you want a rough analogy.
They're a collection of applications that work well together and make
an X server useful. This is analogous to a Linux distribution being a
collection of applications that work well together and make a Linux
kernel useful.

-- 
:wq