Keeping old version of Firefox while updating to new version On my OSx I want to be able to switch version of software I use.

Like right now I have Firefox 29, but I want to try firefox 32. is there a way I can download and install version 32 and keep the old one as well?

How such strategy can be implemented on all softwares ? This gives me leverage to switch to older version with ease..
Older versions of Firefox can be found here:

https://ftp.mozilla.org/pub/mozilla.org/firefox/releases/

There's Multifirefox app, which can help switching profiles for several versions.

Installation:

brew cask install multifirefox



  MultiFirefox is a small launcher utility that allows you to run multiple versions of Firefox side-by-side.  It helps you set up multiple profiles (one or more for each version of Firefox), remembers your last launch preferences for easy launching, has auto-updating built in for when we make improvements, and is 100% open source, MIT licensed.