You can use Firefox Split Browser Addons to split your content into several small windows. You can split as you like on whatever position you want such as left, right, top and bottom position. This is useful for blogger who has a very wide screen resolution or want to view several pages on the screen at the same time such as post page and preview page for WordPress. You don’t need to click the tabs and go back to your page again. Now, you can do your work all on the same screen and this is good for people who like multi-tasking.
The drawback of using this Split Browser Addon is that you will suffer a smaller browsing experience. This is not recommended for people who has poor eyesight or can’t see clearly on smaller browsing window.

You can have tab in the split browser and split as many browser as your RAM and screen can support. Which mean you can enjoy the splitting as you like! You can also do drag and drop links into split browser. Status of split browsers are saved, and automatically restored when you restart your Firefox.