in reply to Tk OSX couldn't connect to display :0
Start your X11.app first.
EDIT:If you work in a terminal-window you can type open /Applications/Utilities/X11.app/ to start the X11.app.
In Section
Seekers of Perl Wisdom
in reply to Tk OSX couldn't connect to display :0
EDIT:If you work in a terminal-window you can type open /Applications/Utilities/X11.app/ to start the X11.app.