www.historicalMaterialism.info I installed Alpha 2 jessie in expert mode
so that I could avoid installing a desktop environment. In package
selection, I deselect a desktop environment. When installation finished
I install fluxbox and use # update-alternatives --config
x-window-manager to select fluxbox manual.

Nevertheless, in spite of that when I reboot I'm taken to a graphical
log in screen and then to some kind of desktop environment. Xfce4 is not
installed.

What is this environment (it has a chartreuse background), and how do I
get rid of it? How do I get rid of the gui login (xdm, gdm, kdm etc not
installed) so that I can run the machine from console without X system?