X11 utilities

Classic X11 utilities that are still useful

X11 has some old tools that are largely forgotten but that are really useful if you are still running lightweight window managers or developing some X11 stuff.

xlsfonts

This will list all available X11 fonts in your system.

editres

Specially useful while developing a X11 application, it will list all the widgets for a given screen.

xfd

Displays all characters for a given font. Invoke it with -fn and the font name.

xfontsel

A graphical tool to select a specific font.

xev

Displays all X events. Useful when developing X11 applications.

xv

Not specifically a X11 tool, but it was once the classic way of taking screenshots in UNIX. The program does exactly the same that it did in the 90s and is still available in FreeBSD. The main screen says it all.

You can see more examples of old (and sometimes totally useless) tools here.