Prior to using Opera, I was a big fan of Firefox. Sadly, Mozilla has failed to understand how truly good tab management can be. Because Firefox is open source, other developers can snag the source, build their own take on the browser, and distribute it. Also: Firefox is finally adding vertical tabs why it's a game changing update I started testing Zen Browser a few months ago, calling it the customizable Firefox I've been waiting for . During those first few weeks, I used Zen...
