While many of these apps are still early in the development process, they're all usable, and in fact, have all acquired fairly substantial user bases in a short time.
What do they have in common? While the apps on our list cover a gamut of categories, we did uncover a few trends.
First, a number of the most successful new open source projects relate to mobility. Several can be used on a USB thumb drive (Appetizer, WinPenPack, UNetbootin), and several others were specifically developed for netbooks (Easy Peasy, eeebuntu, Moblin).
Other applications make it easier to use mobile devices like iPods (SyncDocs, MP4 Creator, Streamy).
Second, quite a few of the applications on the list appeal primarily to enterprise users.
For example, Turnkey Linux offers open source virtual appliances that are primarily of interest to large organizations. And ProcessMaker, AJAX Chat, and LogicalDOC, also focus on the enterprise market.
Third, multimedia continues to be a hot topic. Songbird, cPlay, Kaltura, Elltube, and others aim to help users do more with their audio and video files.
Finally – and we're not sure if this is significant or not – we found two applications designed to make users smarter: gBrainy and Brain Workshop. Could it be that the open source community is getting older and worrying about short-term memory loss (gasp!)?
Without further ado, here's our list of hot, new open source applications.
Appliances1. Turnkey Linux
Turnkey offers a variety of virtual appliances pre-configured for tasks like Web development, content management, messaging, and database management.
It makes it possible to deploy some of the best server-based open-source applications in just minutes. Available appliances include the LAMP stack (Linux, Apache, MySQL, and PHP), Joomla, Drupal, MediaWiki, Apache Tomcat, and many others. Operating System: Linux.
The open source answer to iTunes, Songbird is a music player, store, organizer, and more. One of its best features, mashTape, displays Flickr photos, YouTube videos, biographies, and news articles related to the artist currently playing. Operating System: Windows, Linux, OS X.
This audio player offers outstanding sound quality with a minimalist interface. The Web site also includes extensive information on factors that affect audio playback. Operating System: Windows.
4. MP3 Diags
Have some of your MP3 files become corrupted? MP3 Diags lets you fix many of the most common problems and make other changes. Operating System: Windows.
5. Virtual MIDI Piano Keyboard
Use your computer's keyboard or mouse to play a tune. Note that you will need some additional software and/or hardware in order to get the application to work. Operating System: Windows, Linux, OS X.
No doubt about it, the launch of Google's browser was one of the biggest open source releases of the last couple of years. And while it has a long way to go to match the user base of Explorer and Firefox, its speed and simplicity appeal to an ever-growing number of users. Operating System: Windows, Linux, OS X.
Business Process Management
ProcessMaker helps enterprises simplify their workflows, eliminate paperwork, and become more efficient.
In addition to the free, open-source version, it's also available with paid support or as a hosted application. Operating System: Windows, Linux.
Appetizer launches applications and opens folders from a Mac-like dock instead of the Windows Start menu.
It can also be used with applications stored on USB thumb drives and even includes built-in support for Portable Apps.com. Operating System: Windows.
9. Circle Dock
Launch your programs from a circular dock with great background graphics. It's still in the early stages of development, but worth a look. Operating System: Windows.
Build your own database-based Web applications without writing any code manually. It's easy to integrate into existing Web sites, offers a lightweight footprint, and supports all the major browsers. Operating System: Windows.
11. AJAX Chat
This Web chat software features multiple channels, private channels, private messaging, invitation system, controls for offensive users, custom emoticons, and more. It also integrates easily with popular forum software like phpBB, myBB, etc. Operating System: OS Independent.
12. Samurai Want to see how well your Web applications would stand up to an attack? Samurai collects some of the best open-source testing tools available in a single package. Operating System: Linux.
LogicalDOC makes it quick and easy to set up a Web-based document archive so that you can store, search, and organize your files. Features include scanner support, document signature, version control, and more. Operating System: OS Independent.
This app makes it easy to organize, tag, and search your eBook collection. Input book information manually, or it can automatically find cover art and other info for you. Operating System: Windows.
With more than 30,000 active community members, PrestaShop has quickly developed quite a following. Key features include scalability, an intuitive interface, and lightweight size (around 6 MB). Operating System: Windows, Linux, OS X.
16. Open Auto Classifieds
Designed just for car dealers, this application makes it easy for the non-technically inclined to set up an online vehicle listing with minimal expense. Operating System: Windows, Linux, OS X.
17. Rigs of Rods (RoR)
This truck, car, airplane, and boat simulator uses a unique soft-body physics engine, which makes the simulated vehicles more flexible and lifelike.
Create your own vehicle or drive one of the more than 2000 vehicles that other users have already designed. Operating System: Windows, Linux.
18. Solitaire Greatest Hits
Free solitaire card games for the Mac. It includes Klondike, Free Cell, Spider, Pyramid, Canfield, Aces Up, Golf, Scorpion, Yukon, Baker's Game, or Forty Thieves. Operating System: OS X.
This app aims to keep your mind sharp, no matter what your age. It includes logic puzzles, mental calculation, memory trainers, and verbal analogies.
Note that while there is a Windows version, gbrainy was developed for GNOME and works best for Linux users. Operating System: Windows, Linux.
20. Brain Workshop
Brain Workshop uses the Dual N-Back mental exercise to help you improve your short-term memory and fluid intelligence.
It may help you overcome some of the effects of aging or ADD, but mostly, it's fun. Operating System: Windows, Linux.
21. Open Sonic
Yes, there's now an open-source version of Sonic the hedgehog. While it is different from the other Sonic games, it should be familiar.
Unfortunately, the alpha release has only two levels so far, and the OS X version isn't very polished. Operating System: Windows, Linux, OS X.
Winner of multiple awards, XMind is a brainstorming and mind mapping application that is similar to (and compatible with) FreeMind.
Originally released under a commercial license, it went open-source about a year ago. The latest release includes Web 2.0 and Gantt project tracking features. Operating System: Windows, Linux, OS X.
This app lets you take your favorite open-source apps with you wherever you go on a USB thumb drive. It's similar to the better known PortableApps.com, but it includes a lot more software.
It comes in six different flavors: 2Gb, Essential, Game, School, Web, and Personal. Operating System: Windows.
Part of Cisco's mpeg4ip suite, MP4Creator lets you create and modify MP4 files. With it you can turn existing audio and video files into streams that can be understood by most devices, including PCs, iPods, iPhones, and others. Operating System: Windows.
This media recorder allows you to watch (or listen to) streaming video or audio, download files, and drag and drop files to play on your computer or iPod.
The handy bookmark manager makes it possible to keep track of your favorite sites. Operating System: Windows, Linux, OS X.
Although it's designed primarily for novelists, Storybook helps creative writers of all kinds keep track of characters, locations, and multiple plot lines.
Track plot lines chronologically, organize chapters and scenes, type your manuscript, and more. Operating System: OS Independent.
27. Easy Peasy
Don't like the operating system that shipped with your netbook? Try Easy Peasy instead. It's based on Ubuntu and is optimized for use on the Asus eee. Operating System: Linux.
As you can probably tell from the name, eeebuntu is another Ubuntu-based operating system for the eee netbook. It includes a variety of popular open-source applications, like Firefox, OpenOffice.org, Pidgin, Thunderbird, VLC, Banshee, and more. Operating System: Linux.
Want to give Linux a try without giving up your Windows machine? Or do you want to use an app that only works in Linux? andLinux lets Windows users take the Ubuntu desktop for a spin and run most Linux applications. Operating System: Windows.
30. Portable Ubuntu Remix
Similar to andLinux, Portable Ubuntu Remix lets you run Linux apps in Windows. It's not quite as polished as andLinux, but some people prefer it. Operating System: Windows.
Now managed by the Linux Foundation, Moblin was originally developed by Intel as a Linux-based operating system for netbooks and other mobile devices.
Specifically, it was designed to run (and sell) the Intel Atom processors released in April 2008. Operating System: Linux.
32. Tiny Core Linux
The name says it all – Tiny Core Linux squeezes a desktop Linux into just 10MB. To really use the OS, though, you'll probably have to add extensions, but the app gives you complete control over which extensions you add. You end up with a lightweight, customized Linux distribution. Operating System: Linux.
UNetbootin lets you turn a USB thumb drive into a bootable Linux drive. It supports all of the most popular Linux distributions, including Ubuntu, Fedora, openSUSE, Debian, and several others. Operating System: Windows, Linux.
Need to enlarge a portion of a bitmap image? SmillaEnlarger uses a unique algorithm to blowup images while retaining fairly high image quality. Operating System: Windows, Linux, OS X.
Impressive lets you add eye candy to existing presentations. Simply import your slides as a pdf, and you can add interesting transitions, highlight boxes, and spotlights. Operating System: OS Independent.
36. Parted Magic
This partitioning utility makes it easy to perform tasks like creating and editing drive partitions, formatting hard drives, creating backups, and testing for failures. Operating System: Linux.
Forgetting your Windows administrator password can be a huge pain. Usually, you have to reinstall Windows in order to regain access to the administrator account.
However, this little app will find your administrator password for you in about 5 minutes. Operating System: Windows.
38. Process Hacker
Process Hacker lets you see in detail all of the processes running on your system—including hidden processes—and gives you the ability to pause or terminate them.
It also includes performance graphs so that you can see which processes are consuming the most resources. Operating System: Windows.
39. Java Remote Desktop
You can find a lot of open-source applications that provide remote access capabilities. This one's strong point is that it's based on Java, so that it's easy to work cross-platform whether you're collaborating with a colleague or providing remote helpdesk services. Operating System: OS Independent.
If you use David Allen's "Getting Things Done" method, this to-do list might be for you. The interface is pretty basic, but it can help you get organized in a minimal amount of time. Operating System: Windows.
This application keeps a detailed record of the time you spend on various projects with a minimalist interface. Use it for client billing or to help yourself become more efficient. Operating System: Windows, Linux, OS X.
BleachBit helps you "Clean junk to free disk space and to maintain privacy." Specifically, it erases cache, cleans out your browsing history, deletes temporary files, and more.
It also makes it possible to "shred" deleted files so that they cannot be recovered. Operating System: Windows, Linux.
43. Magical Jelly Bean Key Finder
Need to find your Windows product key (CD key) to reinstall Windows or get support? This handy app will find your key so you can print it out, and the community extensions make it possible to find the keys for a lot of other apps as well. Operating System: Windows.
Compare and synchronize folders very quickly. The interface is easy to use, and it's available in a number of different languages. Operating System: Windows, Linux.
SyncDocs is designed to transfer files from one computer to another over the Web. It's most useful in transferring files to an iPod or iPhone. Operating System: Windows, Linux, OS X.
46. Little Registry Cleaner
Over time, information builds up in your Windows registry that can slow your system or lead to errors. This app cleans up your registry for better overall performance. Operating System: Windows.
47. Kaltura Community Edition
Kaltura Community Edition is an open-source version of the commercial (but still open-source) . With it, you can set up your own video streaming site, as well as managing, searching, uploading, importing, editing, annotating, and remixing video files. Operating System: OS Independent.
Download videos from YouTube and convert them to any format. Elltube supports AVI, MPEG, MP4, 3GP, MP3, WAV, and AMR file extensions. Operating System: Windows, Linux.
49. Video Monkey
This Mac-only app lets you convert video files from one format to another. It's still an alpha release, but works pretty well as it borrows heavily from the old Visual Hub code. Operating System: OS X.