I've read that sid is the unstable 'version' of debian, and by unstable I understand 'under testing'.

However, I have a question.

If I choose to upgrade to Sid, and let's say I install kde today, but tomorrow a newer version of kde is released, when I do a dist update (i don't know how it's called), will it choose to install the new kde automatically?

I want to be able to install relativelly new packages (I guess I could go with sarge) but from time to time I need to install a very recent package. Can I install sarge and install bits from sid also? (like in gentoo, when using ~x86 in portage)

Or do I have to go with sid? (I don't want to update frequently - don't have the connection), but I want to be able to add some new packages.

Sorry if this was already posted
But thank you for clearing this out for me!

Thats right, they get into stable after having been through experimental, which usually means that they actually work. They are then in unstable and get a good hammering, if everthing stands up they make it into testing. Every so often testing is released as the new stable, which means slowing down testing updates, and making sure everthing really works well together, and the last few problems that people may have are hammered out. ( Which is what is happening at the moment )

Its simply an upgrade, and your correct it would install the new version.

You can run a mixed system, of mainly testing and upgrading just specific packages ( and there dependencies as long as they don't break anything else ) from sid. Its a matter of filling out /etc/apt/sources.list with sources for testing and unstable, and adding the line

APT::Default-Release "testing";

To /etc/apt/apt.conf.d/70debconf, then when you want to update/install a package to a version in unstable simply do

apt-get -t unstable install kde

instead of installing a package with
apt-get install kde

Ok. Thank you for clearing that out for me.

I still have a couple of questions:
1)
Is there no way I can install new packages without installing their new dependencies? Or, at least, can I install an older version of a program, that doesn't require me to also install the new kde (for exemple). (I don't want to download a lot!)

2) I noticed that all the packages are precompiled for i386. Isn't that a bit old? (I know it provides compatibility, but it doesn't take advantage of my AMD Athlon XP)... Can I get sources from i686 at least?

3) If I want to install a program, can I get a list of packages it wants to install so I can download them from work? (saving a wget list would be great)

Thank you for your help.

No, they wouldn't work. They whole point of of the deb system is to avoid doing exactly this. An example would be konqueror. You can't install konqueror 3.3.1 on any system that does not have kdelibs4 (>= 4:3.3.1), libart-2.0-2 (>= 2.3.16), libc6 (>= 2.3.2.ds1-4).. plus others, otherwise Konq will not run. If you install Konq it REQUIRES that these dependencies are filled.
You can install older versions of programs, you can also prevent any package from being upgraded, check the APT HOWTO for more information. The only thing you can't do is install a package, without its dependencies being met.
All Debian packages are also available as source ( see the HOWTO ) and you can rebuild them if you wish. The packages where recompiling for specific archs would make a real difference are the kernel and libc which are available. Debian SID currently contains about 16421 normal packages ( This excludes the meta-packages like KDE which are just packages that depend on other packages but don't contain any content ) and for i386 is about 10Gb, Debian already covers 12 arch's. Adding another few sets for tiny differences that make very little if any improvement, would cost a huge amount in developer time and resources.

Explanation of above statement: Compilers can make some optimizations for specific processor stats, but most of the differences between 386 upto 686 are internal and not available to the compiler, they are "in processor stuff". So the improvements are generally little to none. Extensions (3dNow!,SSE ) to the i86 set are very rarely used outside specific programs (codecs, 3d graphics), are written in assembler ( Not C/C++ ) and usually detect what Extensions you have, and alter the code paths to match. How do you think all the commercial ( precompiled only ) software does it? :) and yes I did run Gentoo for a while, but didn't see much improvment over precompiled stuff. It may have just been what I used, and there are of course exceptions to everything, but what I've said is genrally true. What stuff you run on your system (background processes), is more important than having things compiled for your specific processor.

EDIT:
I have now found a way, I should of know apt-get had an option
apt-get install --print-uris -y packagename | grep ftp | sed -e "s/'//g;s/ .*//g" > filelist
On my system, this is what is created for apache:
Is that what you want?

Thank you very much for your explanation.

It was extremely usefull. I'm switching to debian! (You're right, gentoo doesn't seem that fast, even if it was compiled for my system)

I didn't know the switch from i386->i686 consisted mainly of internal stuff... I thought there were added instructions or something else.

Thank you for your help! (an yes, the list you showed was the exact same thing I wanted....)

No, there were really no instructions added of significance ( that's what MMX, SSE, and 3DNow! are for ). Check your processors flags, for a complete list. This basically tells the system what your processor supports.

The main difference between 386/486 and 586 was a move a superscalar design, the 686 added Out of order execution, but as Ars Technica puts it in the Pentium History
Check out the Ars Article, gives a good overview to how Processors have really changed changed.

Thanks for the help. It really painted a new picture of the whole computer business!