Phantom is woefully out of date, you need a polyfill even for Function.bind. Firefox dropped support for Selenium in 47, and chromedriver only supports it with a wrapper called chromedriver.
Are you talking about Selenium WebDriver or Selenium IDE (the record/playback tool for Firefox)? Those are two separate things. Selenium WebDriver implements is a cross-browser W3C-standard and Firefox very much still supports it.
