Hi,
Ancestris is based on Netbeans (basically, this is a bunch of Netbeans plugins), so we inherit of the standard behavior of Netbeans, including fonts definition.
By default, Ancestris use the value of your system.
If you change your global font settings, it should change the one used in Ancestris.
Nevertheless, I finally find a way to change the size of the font by changing the ancestris.conf file.
Go to the ancestris/etc directory, open the ancestris.conf file and add to the line "default_options" the parameter : "--fontsize 24" (the value 24 is given as example, you can choose the one you want, the default value is 11).
Restart Ancestris and you should see the difference.
Warning : I don't have tested extensively this option. It could lead to cut texts and random effect on windows display.
Zurga