Okay, so first I learned that Xvfb wasn't included with my OS X version, so I installed it from http://www.xquartz.org/.
and that seemed to have worked:
which xvfb
/opt/X11/bin/xvfb
But when I try using it with either pyvirtualdisplay and xvfbwrapper, following advice I found on this question How do I run Selenium in Xvfb? My script runs without errors but just opens in a Chrome browser window:
from selenium import webdriver
from pyvirtualdisplay import Display
display = Display(visible=0, size=(800, 600))
display.start()
browser = webdriver.Chrome()
browser.get('google.com')
Am I doing something wrong here?
I believe that Chrome is built for Quartz ui framework, so it ignores the X11 windowing engine. You will need to install an X11 version of a browser and then execute that.