Today I went to the supermakert and while wainting in line, the point-of-sale frozen. Well, it could be disturbing for most people - but I saw the operator rebooting software and it was Linux. I could not realize the distro and I can say that it loads tons of services during start-up (more than I am used to see) After booting, with no login nor any kind of visible window manager, appeared the graphical user interface of POS and continued from the last product registered. OK. It is a long, long history. Well, what I want to know is what is the best way to produce a effect like that in my distro of choice (Ubuntu)? Tons of options suddenly crossed my mind. A Gnome/GTK program using full-screen started at gnome starting. A Java/Swing Application, a xfce application (if such thing exists) and suddenly I figured out that I don't have a clear idea of how X works at all. In Win32 that is just one way to do anything: Win API and Petzold way. Anything else (including .NET) are just layers between app and gdi/kernel. So, what is the learning path to programming X? Could anyone send me a direction? Thanks Valter