> What is the font use Xwindows system default? How can I change
>this font on other font? I use slackware 3.5, X11R6, fvwm95...
>
There are many different fonts. Each program determines its own font.
Fvwm95 uses fonts for menus, the task bar and title bars. These are
configurable from within ~/.fvwm95rc
Read the fvwm95 man page.
If you want to change the fonts used by a particular program then you need to
configure that program separately. Sometimes this uses ~/.Xresources sometimes
app-defaults (although slackware seems to avoid this). Look at the man page for
the program you want to configure.