Gromit-MPX is an on-screen annotation tool that works with any Unix desktop environment under X11 as well as Wayland.

None of the existing display configuration tools does what I think is "the right thing".

• Don't start from a stored config, use xrandr to read the systems' current state
• Allow creating "profiles" that will get applied smartly (not there yet)
• Generate a xrandr invocation to reflect the desired configuration
• Allow per-monitor scaling
• Allow arbitrary monitor positioning
• Implement "scale everything so all the pixels are the same size"

xclip is a command line utility that is designed to run on any system with an X11 implementation.

xclip provides an interface to X selections ("the clipboard") from the command line. It can read data from standard in or a file and place it in an X selection for pasting into other X applications. xclip can also print an X selection to standard out, which can then be redirected to a file or another program.