Tools Development Environment (XSISDK)
The is a special layout specifically designed for users of the SDK environment.
It embeds script editors, Netview, the Plugin Manager, the SDK Explorer, and other developer centric tools directly into the layout. This avoids the large number of floating windows that can get in the way when trying to write complex tools in the standard layout.
Each developer has different style and preferences, so advanced users are encouraged to modify the layout to tweak it to their own specific taste - perhaps you want more script editors, script editors on both sides, your own toolbar for quickly launching your favorite scripts and so on.