We found dozens of great open source tools that let you customize your desktop environment, whether you're ready to try out a whole new operating system or just a new screen saver.
While many of these tools add new features to software you probably already have on your system, others offer brand new functionality, like the Florence virtual keyboard and the PNotes sticky notes. You might even find a open source tool or two that you just can't live without.
Open Source Tools: Desktop Enhancements
If you like to operate from the command line in Windows, Console is a great alternative to cmd.exe. Features include multiple tabs, alpha and color-key transparency, configurable font, and different window styles and backgrounds. Operating System: Windows
Are the Google deskbar and "I'm feeling lucky" button not fast enough for you? Try Dave's Quick Search Deskbar. It lets you search the Internet without opening a browser first, and it has lots of helpful features that speed up search even more. Operating System: Windows
Primarily designed for the Gnome desktop, Florence offers a virtual keyboard on the screen that hides when you're not using it. It's a great tool if you can't use a regular keyboard because of a handicap or injury--or because you just spilled your coffee on it. Operating System: Linux, OS X
4. GeoShell GeoShell replaces the standard Windows interface (start menu, taskbar, system tray, etc.) with a customizable version. As an added bonus, it usually requires fewer resources to run than the standard interface. Operating System: Windows
Kysrun works a lot like Launchy (below), letting you open applications, files, or bookmarks with a couple of keystrokes. As you begin typing, it offers suggestions for what you might be trying to find. Operating System: Linux
6. Launchy Why bother moving your hand all the way from the keyboard to the mouse and back again? With Launchy, you can open applications, documents, and bookmarks with a couple of keystrokes. You'll never need your start menu or desktop icons again. Operating System: Windows
7. LCARS 24 This is the ultimate conversation piece for true Trekkies. LCARS turns an old PC into a talking alarm clock that uses the graphics you've seen on Star Trek. The latest version runs on Windows, as well as DOS. Operating System: DOS, Windows
Have trouble remembering things--like where you left the pad of sticky notes to use for reminders? Leave yourself a virtual sticky note on your desktop instead with this handy app. Operating System: Windows
Open Source Tools: Desktop Gadgets/Widgets
At this site, you'll find a number of gadgets that work with the Google Desktop. They range from the useful (calendar, clock, calculator) to the useless-but-interesting (flower pot, Star Trek star date calculator). Operating System: Windows
As you might expect, this app lets you run Google Gadgets developed for Windows or iGoogle on Linux. Operating System: Linux
11. Kludgets Short for "Klumsy, Lame, Ugly, Dumb, but Good Enough," Kludgets aims to bring OS X-style widgets to Windows. The site includes links to lots of interesting widgets to get you started. Operating System: Windows
In addition to all the basic arithmetic functions, this desktop Linux calculator handles logarithmic functions, complex and infinite numbers, graphing, statistics, unit conversion, data plotting, and much more. It also includes financial calculators, geometric functions, and a currency converter. Operating System: Linux
Open Source Tools: Desktop Search
Beagle searches your documents, emails, web history, IM/IRC conversations, address book contacts, calendar appointments, notes, source code, images, music/video files, archives, and applications to find the keywords you're looking for. It indexes changes to files, conversations, Web pages, etc. as they are made for fast searching. Operating System: Linux
Why waste time searching all the files on your system, when you know you need a document? This application indexes and searches the text of the documents on your PC, very quickly. Operating System: Windows, Linux
This search tool allows advanced queries (probabilistic search, boolean filters, wildcards, ranges on date, time and size) and detects multiple languages, including Asian characters. You can use it to search the Web as well as your personal files. Operating System: Linux
A text-only searching tool, Recoll finds keywords in most documents types, including e-mail messages and their attachments. In other words, you don't need to know the name of the file you're looking for, just some of the text from the file. Operating System: Linux
17. Tracker Built for the Gnome desktop, Tracker organizes and categorizes your files, as well as providing search capabilities. As a result, other apps like photo or music managers can find appropriate content quickly. It also lets you use metadata and keywords to make it easier to find the information you're looking for. Operating System: Linux
Open Source Tools: File Managers
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
Open Source Tools: Linux Desktop Environments
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
Open Source Tools: Operating Systems
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.
Open Source Tools: Screen Savers
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.
34. Pixel City
Fly through a computer-generated city at night. Check out the YouTube video for an overview of how it works and how it looks. Operating System: Windows
This is a collection of psychedelic screensavers with a number of different graphic styles. While some, like Hyperspace, require some pretty powerful hardware, most will run on any average system. Operating System: Windows
For Lego lovers, this screensaver builds a tower out of the popular building blocks. Operating System: Windows
This screensaver features quotes from wikiquote.org. You choose a topic and a language, then get ready to be inspired. Operating System: Windows.
Open Source Tools: Utilities
Ditto is sort of like your regular cut-and-paste clipboard on steroids. It lets you save multiple items on your clipboard for use later and even share clipboard items across multiple computers. Operating System: Windows
This site offers native Windows ports of lots of different open-source apps offered under the GNU license. There are dozens of apps, tools, and libraries available, but many of them fall under the "utilities" category, which is why we put it here on our list. Operating System: Windows
Need to turn off, turn on, or restart your computer at a later time? This app lets you schedule all those functions so they happen automatically and adds several other features as well. Operating System: Windows, Linux
41. Startup Manager
Does it take way too long to start up your PC? Startup Manager gives you control over which applications and processes automatically begin when you power up your system. Operating System: Windows
42. Synergy Have more than one PC on your desk? This application lets you use the same keyboard and mouse to operate both, even if the computers use different operating systems. Operating System: Windows, Linux, Unix, OS X.
Open Source Tools: Wallpaper
43. Google Wallpaper
Type in a keyword, and this app will find related photos through Google and pick one at random to be your new desktop wallpaper. After a user-determined period of time, it refreshes with a new random photo (and yes, safe search is an option). Operating System: Windows
44. izulu Tired of being stuck in a cubicle all day with no view of the outside world? Izulu updates your desktop wallpaper based on current time and weather conditions so that you'll now what's happening outside even if you don't have a window. Operating System: Linux
Wally is a wallpaper changer that loads photos from Flickr, Yahoo!, Panoramio, and other photos services, as well as your local hard drive. It lets you select how often the pictures change, where they appear on the screen, and more. Operating System: Windows, Linux, OS X
Open Source Tools: Windows Managers
Enlightenment is both a windows manager and a suite of libraries for creating your own windows manager. Although it's primarily aimed at desktops, it can also be used on smartphones and other mobile devices. Operating System: Linux.
47. Fluxbox Key features for this Linux windows manager include tabbing, grouping, keycommands, Chainable Keygrabber, fully editable menus, and more. It's also light on system resources for very fast performance. Operating System: Linux.
This window manager focuses on "speed, simplicity, and not getting in the user's way." It supports multiple themes and multiple languages. Operating System: Linux, OS X
VirtuaWin takes the "virtual desktop" concept that is familiar to Unix users and applies it to the Windows environment. It allows users to save up to nine virtual desktops, each with its own set of open applications and other files. Operating System: Windows
With this tool, you can save multiple desktops, each with multiple open applications, and switch between them. It's a great tool for multi-taskers. Operating System: Windows