Virtuoz!

Dexpot turns your monitor into up to 20. It creates and manages virtual desktops and enables you to work far more efficiently and comfortably with many simultaneously opened windows on Windows 95/98/ME and NT4/2000/XP/2003/Vista (incl. x64).

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’). Virtual desktops are very common in Unix/Linux, and once you get accustomed to using them, they become an essential part of a productive workflow.

WindowsPager is a desktop-switcher/pager for Windows to manage virtual workspaces/desktops. It will integrate smoothly into the desktop panel.

Desktops allows you to organize your applications on up to four virtual desktops. Read email on one, browse the web on the second, and do work in your productivity software on the third, without the clutter of the windows you’re not using. After you configure hotkeys for switching desktops, you can create and switch desktops either by clicking on the tray icon to open a desktop preview and switching window, or by using the hotkeys.

TotalSpaces provides a grid of spaces on OSX Lion

Virtual Dimension is a free, fast, and feature-full virtual desktop manager for Windows platform. The main goal of this open-source project is indeed to enhance the Microsoft "Window Manager" up to the level of usual Unix Window Manager, by providing virtual desktops, as well as some additional features, like always on top, window shading...

Mission Control, formerly Exposé, is a feature of the OS X operating system.

KWin is a window manager for the X Window System, and is in the process of becoming a Wayland compositor. It is an integral part, and the default window manager of the Plasma Workspaces, but it can also be used on its own or with other desktop environments.

Brings Mac to Windows.

GiMeSpace Desktop Extenders are scrolling virtual desktop managers and the only virtual desktop/window managers that give you seamless unlimited desktop space. New since version 2 is that you can now also resize your windows without any limitations. You can have for example a window that is 16000x16000 pixels wide. No screen will ever have that resolution!These programs make the panning (pan and scan) function that so many users liked in windows XP available for windows Vista and Windows 7. But now in a more powerful and flexible way!New since version 2.1 is that you can limit the size of your virtual desktop to the space that is used by your application windows. If you use only the space within you visible screen you will not even notice that GiMeSpace is running!All versions require windows XP or later versions except the 3D version that requires Windows Vista or 7 with Aero theme. 64bits is supported since version 2.2. »

Finestra Virtual Desktops is an elegant solution to managing many windows or tasks on Windows. It allows you to divide your workspace up into multiple "virtual" desktops, each of which is easily accessible on the fly. For example, you can keep all of your internet applications open on one desktop, work on another desktop, and games on a third

360desktop is free software that extends Windows as a 360 degree workspace, plus an online environment for creating interative 360 degree wallpaper, with a gallery and a widget platform, for sharing your favorite 360's with everybody.

Sawfish is an extensible window manager using a Lisp-based scripting language. Its policy is very minimal compared to most window managers. Its aim is simply to manage windows in the most flexible and attractive manner possible. All high-level WM functions are implemented in Lisp for future extensibility or redefinition.

DeskSpace is a 3D desktop visualisation tool, allowing you to seamlessly switch between 9 desktops.