Cairo Shell - Cairo is a desktop environment for Windows.
Dexpot - If you don't have Dexpot yet, the new update makes it a must-have tool for Windows, adding a ton of features to your desktop that you never knew you wanted.
Newgen - Newgen is an application that brings the new Metro UI to your desktop.
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').
SharpEnviro - SharpEnviro (or SharpE) is an open source shell replacement system for Microsoft Windows XP...
Sysinternals Desktops - Desktops allows you to organize your applications on up to four virtual desktops.