As scott_karana mentioned, Firefox has been doing "rapid release" since 2011. https://wiki.mozilla.org/RapidRelease There are 3 channels: Aurora (alpha), Beta, and Release. Every 6 weeks, stable features are pushed into the next channel. So there is a new release every 6 weeks, and if you want to live in the future, you can use the Beta or Aurora channel. https://www.mozilla.org/en-US/firefox/channel/
Edit: do you really want your grandkids to be stuck with version 5? :)
Edit: do you really want your grandkids to be stuck with version 5? :)