Yesterday I told you how to tweak Firefox 4 so it would allow incompatible add-ons to run. One of my primary motivations for doing so was the PermaTabs Mod add-on, which I use religiously to keep tabs open from one browsing session to the next. (Ironically, that extension came into being because its predecessor, PermaTabs, was incompatible with Firefox 3.)
Alas, although I was able to get PermaTabs Mod working, it's not working correctly: Any tabs I designate as "permanent" don't change color like they did before.
So I went shopping for a replacement--and found TooManyTabs. It's not quite the same animal, but it's actually a little better. As PC World's Erik Larkin wrote in his review, TooManyTabs "is for the power-browser who likes to keep many Firefox tabs open at once. Instead of keeping all those tabs active, which can eat up your computer's memory, TMT creates a sort of waiting area where tabs can sit--still visible, but using no memory."
I couldn't have put it better myself. When I used PermaTabs Mod, I would routinely "perma" 5-10 tabs--which almost certainly slowed the browser down. TMT doesn't do that, though it effectively offers me the same convenience. What I get is an extra row of tabs that look like the real deal, but aren't actually loaded until I click one (at which point it jumps to regular tab area and opens that page).
There's a bit of learning curve with TMT, so after reading Larkin's overview, I definitely recommend checking out the developer's tutorial page. It's worth the effort; I can already tell that TMT is going to be a fine replacement for PermaTabs. And needless to say, it's compatible with Firefox 4.