Firefox

Custom Search Engines: Firefox now supports adding even more search engines. To add a custom engine, right-click a search field of a supported website and select “Add Search Engine”, or go to Settings > Search > Add (below the search shortcuts table) to manually enter a search URL.

"Settings > Search > Add" was already available in Firefox for Desktop, but you manually had to travel to about.config to add the missing browser.urlbar.update2.engineAliasRefresh boolean and set it to true. You've been able to do this for at least 4 years, and it's worked on Android for a while too.

Maybe they finally finished polishing it up.

Tab unload is neat I guess but it would be nice if it also prevented the tab from loading until you go to it. I often open a bunch of YouTube links in a row, to catch up on my daily channels. So I have 4-8gb of useless browser tabs sitting waiting for me to get to them because I started on my subscriptions page and middle-clicked the last day’s or so worth of videos. It’s not much more work to finish that step and add an extra step to unload all those newly opened tabs, but it would be a nice option to not load new tabs until they’re activated since they already open in the background.

Maybe there’s a config for it somewhere.

Do vertical tabs auto expand/collapse with hover on Windows yet?

Edit: they fixed it! This works now 🎉

Happy to see unload tab!

Wondering if we're are going to get 140 ESR anytime soon?

Did Firefox add stacked tabs yet? (no, not asking about vertical tabs)