The problem: Every day you read news sites / sites which are sorted into articles which you read many of.
Opening an article hides the list of articles. You lose your focus in the article list and after closing the article you need to find your current location in the list again.

The idea to solve it: You use a widescreen display. Split the browser window horizontally. Lock the left tile to the article list. Configure a keyboard button as modifier for clicking links which causes them to open in the right tile.

Finding the solution: Keywords I came up with for searching the Firefox plugins for this are: {Tile,Tiled,Split} + {View,Tabs}.
The popular plugins are sucky, but there is an unpopular one which does the job (although it is very minimalistic and I’d be glad if someone wrote a better, configurable one – it is open source):

(TLDR) The solution: The Split Pannel add-on. Install it. Go to the Firefox menu View > Toolbars > Customize. Drag the button labeled Split to your toolbar. Go to your favorite news site. Click Split > Left. Now press Ctrl+Shift+Leftclick to open links in the right tile. They will also spawn a tab. All tabs which are open can be cycled in the right tile by clicking them normally.

Additional information: Depending on your Firefox settings, you might need to use a different combo than Ctrl+Shift+Leftclick – check this page or just try all possible combinations of {Ctrl,Shift,Alt} + {Left-,Middleclick}. Also press the Firefox shortcut Ctrl+W to close tabs. Use Ctrl+[1-9] to select a tab by its position.

Feature request for people who want to develop a better plugin: Configuration option to make it work with Middleclick only so I can remove my left hand from the keyboard.