Chatbox

This add-on allows you to open windows nested within windows. Slightly better than CoolPreviews as "panes" will remain visible even if you switch tabs... meaning you can be playing RuneScape and still have the chat sitting at the bottom! It's also easier to open the Chatbox in a pane because you right-click on the "Chatbox" link and select "Load in New Pane" and select where - I choose "Below" as it's fits better.

Remember to select the "lock" button next to the X so that it will stay open even as you navigate.

It should be noted that you cannot "CoolPreview" the "Chatbox" link, but you can right-click and "Add to Stack". This adds a little "CoolPreviews" tab next to the scrollbar, I don't know if you can see it in the example, but if you click on this it displays the "Stacked" preview, click on this to open it in a pop-up as I have. The pop up is dynamic, if you hold the mouse over it and use the scroll-wheel it will scroll up the pop-up, without having to select the window. There is a small issue that the CoolPreview feature will open another link very easily... but as long as the Chatbox is still stacked, you can open it again easily. You can change the preferences to change how the pop-up functions, so it's probably possible to avoid this.