Automatically suspend or hibernate tabs in Firefox

Are there any extensions for Firefox that can automatically hibernate or suspend browser tabs (when they haven't been used for a while?) I saw an extension like this a couple of years ago, but I can't remember its name now.

For Firefox >= 59, there is Auto Tab Discard.

Mozilla is already working on a fork of BarTab to make this a built-in feature. Bugzilla@Mozilla – Bug 675539 Automatically unload (stall/hibernate) longly unused tabs to free RAM

Suspend background tabs: https://github.com/KamiIntelligence/Suspend-background-tabs

Suspend tab: https://addons.mozilla.org/en-US/firefox/addon/suspend-tab/

For a summary, you can check this reddit thread: https://www.reddit.com/r/firefox/comments/36qc63/which_tab_suspender/