This Java-based file manager is lightweight and fast with an interface that looks like Norton Commander. It also includes built-in compression and decompression tools to make it easy to work with archived files. Operating System: Windows, Linux, OS X
19. PCMan The default file manager for LXDE, PCMan can also be used with other Linux desktop environments. It's very fast and features a user-friendly, tabbed interface. Operating System: Linux
20. SurF SurF offers several features that you won't find on Windows Explorer, like the tree-based tab views and highlighting of new and recently changed files. However, it also gives you access to all the regular Windows Explorer options on the right-click menu, offering the best of both worlds. Operating System: Windows
Linux-only TuxCommander features a vertical, two-panel, tabbed interface that's available in several different language. It's extensible, portable, and supports large files (greater than 4 GB). Operating System: Linux
22. Gnome What really sets Gnome apart from other Linux desktop environments is its usability. It also offers both developers and business users a lot of flexibility. Operating System: Linux
The KDE Plasma workspaces for desktops and laptops are notable for their use of widgets. Plasma looks good and offers plenty of flexibility and opportunity for customization. Operating System: Linux
24. LXDE Short for "Lightweight X Desktop Environment," LXDE offers an extremely fast desktop for Linux/Unix systems that doesnt consume a lot of power or memory. Because it can run on hardware with minimal specifications, it's also a good choice for cloud computing. Operating System: Linux
Like LXDE, Xfce is designed for fast performance, and the components can be used together or separately. Its applications include the Mousepad text editor, Thunar file manager, Orage calendar, and Midori Web browser. Operating System: Linux
26. andLinux For Windows users who are curious about Linux, andLinux makes it possible to experience Linux, and use Linux applications, without giving up Windows. It runs on Windows 2000 or later, including 7.
27. eye os
Eye os calls itself "Open Source Cloud Computing's Web Desktop." Essentially, it's a platform for running applications that can be accessed through any browser.
28. Fedora Fedora is the free version of the better known Red Hat Linux, and it's also the basis of the One Laptop Per Child operating system. The laptop features a vast amount of resources for anyone using Linux for the first time and for experienced pros looking for advanced help.
Novell sponsors a free version of their SUSE Linux distribution--open SUSE. It's also available in a retail edition that includes 90 days of support to get you started.
One of the most popular Linux distributions, Ubuntu offers outstanding speed and usability. It's also available in new cloud editions for enterprise users.
31. Electric Sheep
With this screen saver, your computer communicates with thousands of other computers to create animations known as "sheep." You can also vote for your favorite sheep, causing them to live longer and reproduce more often. Operating System: Windows, Linux, OS X.
The My Pictures Slideshow screensaver in Windows has one big drawback--it uses ALL the photos in your "My Pictures" folder. This app lets you decide which pictures will be used by the screensaver, and it also lets you use videos. You can even create a slide show that will appear as your desktop wallpaper. Operating System: Windows
Based on The Matrix Reloaded, this screen saver features the familiar falling green characters that form images of actors from the movie. Operating System: Windows, Linux, OS X.