KDE and Gnome are different ways of doing the same thing - managing your
desktop; You will find disciples of both.

Basically - and I know I'm over generalising here - Gnome is simpler
while KDE is more configurable. However, you don't need to worry which
version of Ubuntu you're downloading as you can install both at the same
time then, when you logon, you can choose which to log into. My advice
is to try them both and see which you prefer.

As to applications, so long as you have the appropriate KDE/Gnome
libraries installed, you can pretty much run any KDE app under Gnome and
vice versa.

My reasons for the question is a particaler problem I came
accross with Kubuntu and solved it with Ubuntu. I want to use KDE4 hence
my question. I'm now copying the thred in full in the hope for answers.
I hope you don't mind me "attaching myself" to your question.
*I asked this question on the kubuntu forum but I would like to hear
opinions of Ubuntu users as well. I had problems connecting to the net
using a static address when I installed Kubuntu. With ubuntu I don't
have those problems . My question isn't about solving that problem. It
is about installing KDE4 in Ubuntu. I really prefer KDE to Gnome (no
offense to anyone) so I want to know will installing KDE "convert"
Ubuntu to Kubuntu ar will there still be differences between the
"conversion" to the original Kubuntu installed from scratch.
I hope this question isn't OT.

I installed Ubuntu 8.04 and added Kubuntu from the repositories. When I log out
I can change the session at the bottom from either Gnome or KDE. Otherwise you
will get the last run desktop manager. I also have KDE 4, XFCE, Fluxbox and
Sugar installed. I don't use the others all of the time, but I like to use them
enough to be of help to others.

Gnome or KDE is chiefly about personal preference. They are equally powerful,
but KDE is more configurable and flexible. It has more tools out of the box as
well. Linux Torvalds, the founder of Linux, prefers KDE, but that does not mean
that you should. It is what works for him. I suggest that you give them both a
spin and see for yourself. I cannot decide and I have been using them for over 7
years. I flip flop and use each for variety.

I like KDE 4 and see much potential in it, but it is still not ready for prime
time IMO. It is still a bit buggy and it is not as configurable as KDE 3. It is
faster, though and is much improved over when it first came out. Then, it was
large and clunky and you could not configure anything. It is getting better all
of the time. They hope to release a Windows version this year. how is that for
ambition. Soon Windows and Linux can share the same look and feel!

XFCE and Fluxbox are good for computers where resources are limited. They work
fast and well, but are not feature rich. Sugar is the OS on the OLPC computer
and is a toy, although I know of someone who programs on it. You can also
install Enlightenment which is something to try once you get some experience. It
is for people who want to take more ownership over the interface. There are a
host of other managers as well.

You can run more than one at once and some will even operate inside others.
Ctrl-Alt-F7 or 8 will switch between two different sessions. For example, in
some distros you can run as user in one and as root in another and switch
between them with a keypress. Don't try that until you are more experienced,
though. Ctrl-Alt-backspace kills any session and brings you back to the login
screen.

"Gnome or KDE is chiefly about personal preference." I have read in
places that KDE is less stable than Gnome. BUT is there any truth in
this? It seems strange to me that Canonical seem to push gnome rather
than KDE... but when stability is raised there seems to be little
factual feedback. I have switched to KDE for no reason other than most
of the apps i use happen to be KDE... thus installing Kubuntu saves me
downloading a lot of the extra dependencies for running certain apps
on gnome.

OK, so Gnome and KDE are more than just desktop appearance then.

Some apps will only run under one or the other? Or is it all will run
under one, but only some the other? If it is a Gnome app, do I need
special libraries to run it under KDE?

I've seen a bunch of the fancy desktop effects on linux-tube.com.
Would those be KDE stuff?

I'm a ways away from playing with that stuff. I just got 8.04
installed on an Athlon 64 system. Not sure if it will support it, or
not. But right now I'm just tickled that the video/audio/internet are
working fine.

Next will be getting the printer going....

"Some apps will only run under one or the other?"

I may not have been clear... The point i was making is that e.g. k3b
(the burning programme) is a KDE app, when installed on gnome it will
need to install quite a lot of dependencies - compared with the number
that it will need to install if installed on KDE [but it is installed
on KDE by default].
Hence installing Kubuntu saves me downloading a lot of the extra
dependencies for running certain apps on gnome.

What i wish to know is the stability between them.

I wrote this question on several forums and as I have now "solved" the
problem i.e. successfully loaded Kubuntu with internet connection onto
my computer. As the problem (from my point of view) is no longer I want
to detail the problem and the solution I used for the benefit of others
AND to thank the many people on these various forums that gave advice
which helped me and set me on the right track. So first of all thank you
all!
The problem I came across:
I installed Kubuntu and was unable to set up my static IP address in
order to connect to the internet. I tried every possible way that I knew
or was advised to try on various forums.
The main problem was with knetworkmanager. I could not get it to allow
me to get into manual setup. What happened was that when going to
knetworkmanager and trying to operate manual setup I was asked for my
password which I typed in. The request closed and then NOTHING happened.
No reaction at all from the manager. So I was unable to setup my static
IP that way.
I then tried to write my static IP in /etc/network/interfaces. My static
IP starts with 10.* etc. but the static IP number I got when restarting
my computer was 198.* etc. No connection to what I had tried. All this
was on a wired connection.
In desperation I installed Ubuntu and had NO problems with setting up my
static IP. I prefer the Kubuntu interface and programs so I tried this:
I then installed KDE4 using
sudo apt-get install KDE4
After seeing that KDE4 worked properly I went to the next step and
completely installed Kubuntu from within Ubuntu
apt-get install kubuntu-desktop
I am very satisfied with the results although I haven't tried out
everything yet. In particular I haven't tried knetworkmanager but when I
get home from work I will do just that.
I intend to send this letter as a bug notice to Kubuntu if I can find
out how(where) to do this.
I hope this can help others as I was helped here.

If you install a KDE app and are running Gnome it will automatically install the
KDE-core files needed to run it. So it will always run, but it may not look the
same as in KDE because KDE and Gnome use different toolkits. Gnome uses the GTK
toolkit and KDE uses QT. You can configure KDE so that it uses GTK instead of QT
to make Gnome apps look like they do in their native window manager. I don't
think that you can do the same in Gnome, but I may be wrong.

If you are using a compositor, such as Compiz Fusion, you can choose to use any
window manager such as Metacity (Gnome), Kwin (KDE) or some other window manager
and whatever decorator such as GTK, QT or Emerald that you may have installed
and no matter what you are in, KDE or Gnome, windows and programs will look much
the same. However, the desktop will continue to look like Gnome or KDE.

I hope that I have not made this too confusing. Linux is modular. Everything is
layered and it is very flexible in how it can be configured. However, KDE is
more flexible than Gnome which can be a good thing or a bad thing depending on
how you view such things. Sometimes more is less and less is more.

I use both interchangeably. One is not better than the other. They are just
different. People like Gnome for its simplicity and KDE for its configurability.
I have not had a problem with KDE or Gnome on a stable Linux distro. In
experimental releases I have experienced problems with each.

The best thing to do is try them both out. You can install Kubuntu from Synaptic
or 'sudo apt-get install kubuntu-desktop' from a terminal. If you install
Kubuntu instead of KDE you get the same thing as if you installed Kubuntu from
the outset. It includes KDE plus all of the packages that Kubuntu team have
selected including: OpenOffice, Kontact, Konversation, amaroK, K3B, and more. If
you install KDE you will get: kde-amusements, kdeaccessibility, kdeaddons,
kdeadmin, kdeartwork,
kdegraphics, kdemultimedia, kdenetwork, kdepim, kdesdk, kdeutils,
kdewebdev, kdevelop3 and the kde-core metapackage. If you install just kde-core,
then you get the bare minimum to run KDE applications from Gnome. If you have
the hard drive space it is a good investment in time and effort to install both
to see which you prefer. Once you decide you can delete which ever you want or
keep them both around.

At some point in the installation process it will ask you to choose your desktop
manager. KDE used KDM and Gnome uses GDM. It does not make a difference as far
as I can tell which you select. Both KDM and GDM work with either window
manager.

You said
"If you install just kde-core, then you get the bare minimum to run
KDE applications from Gnome."

If i'm using ubuntu without kde-core - install first say Kopete and
then say install Kmail. Would the common dependencies in Kmail be
installed again, i'd guess not - if that's the case i'm not sure that
i see the point in kde-core. I thought the package manager would check
to see if each dependency is there and install as necessary.

If you install a KDE application from the repositories in Gnome and afterwards
check your installed packages using the filter or if you do a search for
kde-core in Synaptic, then you will find that kde-core has been installed since
it is a necessary dependency. Once it is installed then it will not need to be
installed again and other KDE applications will install. Some other KDE
applications will need more of KDE in order to operate and as you add
applications you will eventually end up with enough KDE to be able to run it
from the session manager.

I found this out when I was using Hardy last January or December when it was
very experimental and it included KDE 4 for the first time. I could not get KDE
4 to install because of dependency problems between kde 3 and kde 4. I wanted to
see what some of the applications were like, so I began to install them
individually, those that would install.

I was surprised one day to see that KDE 4 appeared as one of the window managers
under session at login. So I changed the session to KDE 4 and it loaded, but
without full functionality. I had no taskbar or configuration, but could add
widgets and run programs. Eventually the dependency problems sorted themselves
out and I was able to install the full KDE desktop with all of the bells and
whistles.

What had happened was that update manager would present me with a list of
updates. Most of them were ones already on my system, but occasionally one would
appear in the list that said, not installed. If I told it to update with
de-selecting it, it would add a piece of KDE 4 and as the pieces began to grow
and KDE 4 began to take shape.