Raspbian Linux
Raspian is a special customized version of Debian for the Raspberry Pi. By default, this image includes a graphical user interface and some tools like media players and web browers. For some use cases (e.g. servers) this might be not needed. It's also a security breach if you run a server.
I want to use a Raspberry Pi as Icinga server - therefore I don't need a graphical user interface.
If you're too lazy to find out which packages are not required you might use the following commands to delete optional (graphical) tools packages:
1# sudo apt-get remove --purge alsa-* gnome-icon-theme gnome-themes* gsettings-* hicolor-icon-theme lxde* midori* nano openbox omxplayer pulseaudio* wireless-tools wpa* xserver-* zenity* lxappearance lxinput lxmenu-data lxpanel lxpolkit lxrandr lxsession* lxshortcut lxtask lxterminal mupdf menu menu-xdg netsurf* penguinspuzzle smartsim scratch usbmuxd xarchiver
2# sudo apt-get remove --purge xterm leafpad
3# sudo apt-get remove --purge avahi* gksu* libgl1-mesa-glx libglapi-mesa libjack-jackd2-0
4# sudo apt-get remove --purge dillo libcaca0 libcairo2 libcroco3 libflac8 libfltk1.3 libfontenc1 libfreetype6 libgdk-pixbuf2.0-0 libgdk-pixbuf2.0-common libjasper1 libjpeg8 libmad0 libmikmod2 libogg0 libopenjpeg2 libpixman-1-0 libpng12-0 libportmidi0 libpulse0 librsvg2-2 librsvg2-common libsdl-image1.2 libsdl-mixer1.2 libsdl-ttf2.0-0 libsdl1.2debian libsmpeg0 libsndfile1 libtiff4 libvorbis0a libvorbisenc2 libvorbisfile3 libx11-6 libx11-data libx11-xcb1 libxdmcp6 libxfont1 libxft2 libxinerama1 libxrender1 x11-common xauth xdg-utils xfonts-encodings xfonts-utils xinit xpdf
5# sudo apt-get autoremove --purge
My installation includes Apache, PHP and Icinga and fits on a 1 GB card. 🙂