Tree style tabs are user interfaces where the tabs appear vertically on the left side of the user interface, where opening links in a new tab opens in a sub-tab to the tab one is in, and where one can collapse an entire tree of tabs, to allow much better organisation and efficiency. This style of tab browsing is amazing, and once you go to it, it is likely you will never want to go back.
Unfortunately, this is usually done through addons, new addon systems are not as amiable to user interfaces as old ones, and the browsers that do still have working, well-integrated tree style tab solutions are slowly becoming old and incompatible with newer extensions due to lack of development. We must change this. Please help!