Most personal computers have a version of the operating system Windows, from Microsoft, installed on their hard disks. There are alternative operating systems, such as Apple Mac OS X, however it needs special computers only sold by Apple. Another alternative is various free clones of the operating system UNIX, which was created in the beginning of the 1970's. There are different versions of BSD UNIX which are built from a UNIX kernel. The most popular alternative to MicroSoft Windows is the operating system GNU/Linux. It is built on the operating system kernel Linux which is a UNIX clone and was initially developed by Linus Torvalds. The first version of Linux was released to the world in 1991. Other software surrounding the Linux kernel is usually GNU based and free.

The Linux kernel

The Linux kernel is a fully featured UNIX clone which uses modern operating system techniques. The Linux kernel is tailored to a large number of architectures. The source code of the Linux kernel is freely available according to the GNU General Public License ("GNU GPL").

Linux distributions

A number of different companies and organisations assemble distributions of the Linux kernel and other programs included in the operating system such as application programs. Some of these companies and organisations also develop different software. Examples of distributions are Redhat, OpenSuse, Mandriva, Fedora, Slackware, Mint, Ubuntu  and Debian. Some companies charge for their work of putting together the distribution.

Debian GNU/Linux

Debian GNU/Linux is a non-commercial distribution of the operating system kernel Linux and software, mainly from the GNU project. About 1000 unpaid developers stand behind the distribution of Debian GNU/Linux. Of course there are many more developers who work with the free GNU and other software that is supplied by the Debian distributionen]. Currently DSV uses version 9.0 of Debian GNU/Linux, commonly referred to as "stretch".

DSV's GNU/Linux environment

DSV's personal computers in the computer rooms have two operating systems, Microsoft Windows and Debian GNU/Linux. When booting up the computer you can choose which operating system you want to use (dual boot). If you choose Linux as operating system the Linux kernel will load and a graphical X bsaed window will be displayed on the screen, along with a login window (GDM). There you enter your Stockholm University user name and  password to start the graphical desktop environment.

Desktop environment

UNIX has existed as an operating system since 1969. In the beginning all work was done with text based commands and a command shell against the UNIX kernel. Nowadays there are also graphical desktop environments that are similiar to and even surpass MS Windows' graphical environment. Contrary to Windows, in GNU/LInux the user can choose between different desktop environments or simply window managers. For Linux computers the desktop environment GNOME is default and the one which we recommend. If you however are used to another environment such as KDE, FLuxbox, Windowmaker or others you are free to choose from them.


The Debian GNU/Linux distribution contains about 8700 different packages with software. In DSV's environment there are abut 1600 Debian packages installed. There is for example software for text editing, software development, graphics, Office-clones, web browsers, e-mail clients, database management and more. Se this webpage.

The GNU/Linux server triton

It is possible to connect to DSV's GNU/Linux server from home. You can connect in text-only mode with a SSH client. If you have an X server running on your computer you can execute graphical software on triton and have it displayed locally. Se more on DSV's web pages about Linux.

Web links with more information