This provides ability for you to split Firefox's window as you like. This will help you in various cases, for example, to read both top and bottom parts of a web page, to compare two web pages, to browse web pages beside your favorite movie, and others.
Specifically, this simply binds multiple windows like a window, it is the core feature of this addon. When you move or resize a window, then Fox Splitter re-aligns others synchronously.
If you see any problem, see FAQ at first. If there is no solution, post a report to the issue tracker on the GitHub please.
Released version includes following language packs:
Drag tabs or links to a window edge, then drop marker will appear. After you drop it, the window becomes split.
Split windows. You can split windows more and more. If you resize (or move) a member window, then others are also resized (or moved). They are synchronously raised on windows of other applications, so you don't see "wrongly backgrounded behind another application" windows.
If you want to change splitting order and position, drag the "Split" toolbar button itself or the Firefox button. You'll see the drop marker same to dragging of tabs. After you drop it, the window will moved to the position.
More commands also available to split windows, without drag and drop.
Scroll bars in split windows can be synchronized. When you press down the "Sync Scroll" button on the toolbar or the "Synchronize scroll status" item in the menu of the "Split" button for some member windows, then all of them are scrolled if one of them is scrolled.