[Programmatic]

Tree-style tab and middle clicking means that you can have a hierarchical record of your browsing when researching. Middle click three to five tabs from a search, middle click from each tab when reading through on the first article for any interesting subarticles, then when you get to the bottom you have a visual record of your path to that point.

To make things even better, when you're done with that research point you just kill the parent level tab and the children all go away too.

Tens of tabs is pretty typical in my workday and improves my productivity vs. fewer tabs and forgetting how I got to a tangent.