Why does apt-get doesn't work in other linux?
 

OK, i know apt-get works on ubuntu but it doesn't seem to work on other linux distributions.. :( Why is this??

apt-get is debian based package manager. If you use some other distribution you should be using the package manager of that disto.

Here is a list of some "deb" based distros
http://www.debian.org/misc/children-distros
They use .deb packages and apt-get/aptitude/wajig are some deb package managers.
The other main packaging system uses rpm packages and yum is a package manager for those systems which include OpenSuse, Fedora, Mandriva, etc.

Google really really really is your friend.
cheers,
jdk

Thanks for the info :) Is Package manager a program?

Yes, it's a program designed to track all the installed packages on your system and take care of a few things: updates and dependencies - i.e., some packages need functions provided by other packages to work properly. The package manager is there to take care of that. The whole system is explained pretty well on Wikipedia (link), if you want to know more - check it out.

Yeah you can call it a program.

http://en.wikipedia.org/wiki/Linux_d...ion_comparison

further down is a list of which packet manager with which distro

two things; there are packages, and packages must be in a format. A package manager is a program (...maybe a suite of programs...) which has to understand the format of the package(s) that you intend to use (and stuff about which libraries are already available, etc, etc).

So debian, and pretty much everything directly descended from it, uses the .deb format and the programs on that platform understand that. It used to be that the only other format that was in popular use was RPM (originally the Redhat package manager, but now the RPM Package Manager, apparently) but now there are a few others with 'small market shares'.

Most package managers only understand one format, but there was something called SMART (& there may be others) which tried to be cross-platform; haven't heard of any development on that recently, though.

One confusion that is often made is that the format and the package manager are not the same thing (particularly on RH-like platforms where you can use the RPM command line utility to manipulate RPM packages); the manager has to understand the format, but they are not the same thing.

So, to your original question, the utils that the *bunutus have from debian work on pretty much any debian-derived platform, but not on the RPM platforms or the other smaller ones.