# Selecting and Installing Software

During the installation process, you are given the opportunity to select additional software to install. Rather than picking individual software packages from the &num-of-distrib-pkgs; available packages, this stage of the installation process focuses on selecting and installing predefined collections of software to quickly set up your computer to perform various tasks.

These tasks loosely represent a number of different jobs or things you want to do with your computer, such as Desktop environment, Web server, or SSH server

You should know that to present this list, the installer is merely invoking the `tasksel` program. It can be run at any time after installation to install more packages (or remove them), or you can use a more fine-grained tool such as `aptitude`. If you are looking for a specific single package, after installation is complete, simply run `aptitude install `package``, where `package` is the name of the package you are looking for.

. tasksel-size-list lists the space requirements for the available tasks.

Some tasks may be pre-selected based on the characteristics of the computer you are installing. If you disagree with these selections you can deselect them. You can even opt to install no tasks at all at this point.

In the standard user interface of the installer, you can use the space bar to toggle selection of a task.

The Desktop environment task will install a graphical desktop environment.

By default, &d-i; installs the Gnome Xfce desktop environment. It is possible to interactively select a different desktop environment during the installation. It is also possible to install multiple desktops, but some combinations of desktop may not be co-installable.

Note that this will only work if the packages needed for the desired desktop environment are actually available. Installing any of the available desktop environments this way should work fine if you are using a DVD image or any other installation method with a network mirror.

The various server tasks will install software roughly as follows. Web server: `apache2`; SSH server: `openssh`.

The Standard system utilities task will install any package that has a priority standard. This includes a lot of common utilities that are normally available on any Linux or Unix system. You should leave this task selected unless you know what you are doing and want a really minimal system.

If during language selection a default locale other than the C locale was selected, `tasksel` will check if any localization tasks are defined for that locale and will automatically try to install relevant localization packages. This includes for example packages containing word lists or special fonts for your language. If a desktop environment was selected, it will also install appropriate localization packages for that (if available).

Starting with Debian Trixie, &d-i; allows to install Debian Pure Blends directly. There is an entry Choose a Debian Blend for installation at the bottom of the tasks list, which enables an additional choices dialog to appear, after `tasksel` has finished.

In that dialog (`blendsel`), you can choose which blend to install, similar to this tasks selection.

See the Debian website for more information about Debian Pure Blends.

Once you've selected your tasks, select &BTN-CONT;. At this point, `apt` will install the packages that are part of the selected tasks. If a particular program needs more information from the user, it will prompt you during this process.

You should be aware that especially the Desktop task is very large. Especially when installing from a netinst CD image in combination with a mirror for packages not on the netinst, the installer may want to retrieve a lot of packages over the network. If you have a relatively slow Internet connection, this can take a long time. There is no option to cancel the installation of packages once it has started.

Even when packages are included on the installation image, the installer may still retrieve them from the mirror if the version available on the mirror is more recent than the one included on the image. If you are installing the stable distribution, this can happen after a point release (an update of the original stable release); if you are installing the testing distribution this will happen if you are using an older image.