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I have a project that requires a Debian device to run one simple custom app on a touchscreen from boot to death. It shouldn't be possible to exit the app.
I've looked into Gnome, KDE, XFCE, and Tcl/Tk, but it's hard to tell which are the best for a single app rather than an entire desktop. What are the best options out there?
Bonus points if the solution is in any way easy to program and/or better than average on security.