XFree86, xorg and X Window System
 

I have noticed that on my Slackware 10.0 the conf-file is called xorg.conf and on Debian it was called xfree86.conf (and the tool to config was called xf86config).

I am now reading about this and it doesn't make sense. What is the difference between xorg and xfree86? What is X Window System?

Can someone make things more clear to me, please?

xorg and XFree86 and different implementations of the X windows system. X is the underlying mousey clicking pointy shiny stuff. xorg is a very recent fork of Xfree86 and they are currently interchangeable. currently XFree86 is being replaced with xorg for licensing reasons.

Ok, but the book I am reading mentions X.org and how XFree86 was some kind of part of the X.org organization (if I got it right at all). The confusion for me was if there is a difference between X.org and the xorg.conf-file on my system.

Btw, the book mentioned the tougher licenses but in a more complex way then you mentioned it, sometimes I don't understand way people have to make some things so hard. But thanks anyway. :)