VirtuaWin - VirtuaWin is a virtual desktop manager for the Windows operating system (Win9x/ME/NT/Win2K/XP/Win2003/Vista/Win7/Win10). A virtual desktop manager lets you organize applications over several virtual desktops (also called 'workspaces').
Virtuoz - Virtuoz was designed to be a minimal and robust program that allows to have more than one desktop...
Sysinternals Desktops - Desktops allows you to organize your applications on up to four virtual desktops.
DisplayFusion - DisplayFusion will make your multi-monitor life much easier.
9Desks - up to nine virtual desktops
Ultramon - UltraMon is a piece of software built to help with the management of multiple screens on the same computer system. Without software like this, taking full advantage of an expanded desktop space can be difficult.