Zweiter ChatFrame gefällig? Dem Autor dieses Addons nach, war die Funktion schon "fast fertig" in der Default UI, er hat sie nur gefixt und zum Laufen gebracht
Beschreibung des Devs...
ZitatAlles anzeigenAllows creating multiple chat windows, not just a single window with multiple tabs. Each window can have multiple tabs if desired.
To create a new window, simply drag the desired tab off and a new window will be created for it. You can move the current window by dragging the first (left most) tab.
Disclaimer: Most of this functionality is actually already in the game, it just wasn't fully finished and had some bugs. I just finished it and got it working.