You can grab a copy of Firefox 57 Nightly in portable form so it won't affect any local stuff from PortableApps.com here: https://portableapps.com/apps/internet

You can grab a copy of Firefox 57 Nightly in portable form so it won't affect any local stuff from PortableApps.com here: https://portableapps.com/apps/internet/firefox-portable-nightly https://portableapps.com/apps/internet/firefox-portable-nigh... It's a great way to test out the features in a lower risk fashion. You can do the same with Beta, Dev, and ESR channels as well.