92 Open Source Apps That Replace Everyday Software

If you've never tried open source software, you might think that free applications couldn't possibly be as good as those you pay for. This list might change your mind.

Nearly two years ago, we put together a list of 75 Open Source Tools to Replace Apps You Use Every Day.

This year, we made that list a little longer, edited out some of the projects that are no longer actively maintained, updated our descriptions and added some newer projects.

On this list, you'll find a mix of apps for home users, schools, small businesses and enterprises. These applications are all noteworthy for their ease of use and overall quality. In fact, you might even find some that are arguably better than their commercial counterparts.

If you know of other open source projects that you think should be on the list the next time we do an update, feel free to make a suggestion in the comments section below.

Audio/Music

1. Amarok Replaces: iTunes
Like iTunes, Amarok helps you manage and play your music. It integrates with a large number of Web services, including Last.fm, Ampache, Magnatune, Echo Nest and others, so that you can discover new music, and it offers a unique dynamic playlist feature that allows you to search for and play songs by typing phrases like "tracks from around the year 1982." Operating System: Windows, Linux, OS X

2. aTunes Replaces: iTunes
Java-based aTunes offers a customizable, intuitive user interface for organizing large music collections and playing most types of audio files. Notable features include a karaoke function, an easy-to-use navigator for finding songs and artists quickly, multiple playlists, filters, Last.fm integration, podcast support and advanced statistics about songs played. Operating System: OS Independent

3. Jajuk Replaces: iTunes
Critically acclaimed Jajuk has been called "a powerful iTunes replacement" and "the most powerful jukebox out there." Designed for those with large or scattered music collections, it's extremely fast and intuitive and offers helpful functions like the digital DJ rules-based playlist, advanced rating system, smart shuffle, quick copy and more. Operating System: OS Independent

4. Songbird Replaces: iTunes
Because it also comes in an Android version, this iTunes replacement lets you sync your music collection between your desktop and your smartphone or tablet. It boasts an attractive interface, integrated artist info and the ability to purchase tracks or concert tickets right from the app. Operating System: Windows, OS X, Android

Backup

5. Amanda Replaces: CommVault Simpana, Arkeia, Barracuda Backup Service, Zetta
Amanda calls itself the "most popular open source backup and recovery software in the world" and boasts more than 500,000 users. In addition to the free open source version, it's also available in a supported enterprise version or as a hosted cloud-based service through Zmanda. Operating System: Windows, Linux, OS X.

6. Areca Backup Replaces: Carbonite, Nova Backup, Acronis True Image
Best for home users, Areca Backup offers a simple but flexible interface for backing up a single PC or a network. It offers encryption, compression, Delta backup capabilities, as of date recovery and more. Operating System: Windows, Linux

7. Clonezilla Replaces: Norton Ghost
Clonezilla's developers specifically designed it as a replacement for Norton Ghost. This bare metal backup and recovery program comes in two free versions: Clonezilla Live for backing up or cloning a single PC and Clonezilla Server for backing up networks or cloning multiple PCs at once. Operating System: Linux

Blogging

8. WordPress Replaces: TypePad
Used by more than 60 million bloggers, WordPress is one of the best known blogging applications available. You can download the software for free and host it on your own Web server or you can use the hosted service available through WordPress.com. Operating System: OS Independent

Browsers

9. Firefox Replaces: Internet Explorer
Available in both mobile and desktop versions, Firefox offers better speed, personalization and security than Microsoft's browser. Key features include the "Awesome Bar" for easier Web searches, tabbed browsing, one-touch bookmarking and more. Operating System: Windows, Linux, OS X, Android.

Compression

10. PeaZip Replaces: WinZip
While WinZip creates just one type of files, PeaZip can write to 12 different archive formats and read more than 130 different kinds of compressed files. It also supports self-extracting archives, strong encryption, two-factor authentication, secure deletion and other functions. Operating System: Windows, Linux, OS X

Content Management

11. Alfresco Replaces: Sharepoint
Used by companies like Toyota, Fox, Land's End, Marriott, Merck and many others, this multi-function solution combines document management, records management andWeb content management with a number of other enterprise collaboration features. The core software is available for free, but paid support, training, consulting and a cloud-based version are also available. Operating System: Windows, Linux, OS X

12. Drupal Replaces: OpenText,Sitecore CMS, Kentico
With more than 630,000 users and developers in its community, Drupal is a tremendously popular Web content management system. Its users include publishers like the New York Observer and Popular Science, universities like Harvard and MIT, and well-known brand names like MTV and AOL. Operating System: OS Independent

13. Joomla Replaces: OpenText,Sitecore CMS, Kentico
Approximately 2.7 percent of all websites use this very popular open source Web content management system. Version 1.7 offers easier installation, one-click version updating, automatic form data validation, batch processing and more. Operating System: OS Independent

14. XOOPS Replaces: OpenText,Sitecore CMS, Kentico
XOOPS (an acronym for "eXtensible Object Oriented Portal System) is a modular, database-driven Web content management system with a large user base and an impressive number of awards to its credit. It also offers excellent personalization capabilities, a skinnable interface, versatile group permissions and support for multiple languages. Operating System: OS Independent

Customer Relationship Management (CRM)

15. SugarCRM Replaces: SalesForce.com
Used by more than 250,000 customers, SugarCRM offers the full range of features you would expect in a top-notch CRM solution, plus better flexibility and no vendor lock-in. In addition to the free community version, it comes in several different paid versions that can be deployed on premises or in the cloud. Operating System: Windows, Linux, OS X

16. vtiger CRM Replaces: SalesForce.com
VTiger boasts that it is "one of the most dynamic and customizable CRM solutions with the lowest cost of ownership available today." It's available in open source, on demand and mobile versions. Operating System: Windows, Linux, iOS, Android

Database

17. Kexi Replaces: Microsoft Access, Filemaker
Intended as a replacement for Access and Filemaker, KDE's Kexi offers rapid database application development. Features include migration assistants for transition from other databases; support for parametrized queries, lookup columns and simple templates; and visual designers for tables, queries and forms. Operating System: Windows, Linux, OS X

18. MySQL Replaces: Microsoft SQL Server
The "world's most popular open source database," Oracle-owned MySQL offers high reliability, high scalability, security and ease of use. It's downloaded more than 65,000 times every day, and it's won numerous awards. Operating System: Windows, Linux, Unix, OS X

19. PostgreSQL Replaces: Microsoft SQL Server
Now more than 15 years old, PostgreSQL has won numerous awards for its reliable, sophisticated, standards-compliant database. Notable features include multi-version concurrency control (MVCC), point in time recovery, asynchronous replication, nested transactions (savepoints), online/hot backups, support for international character sets and much more. Operating System: Windows, Linux, Unix, OS X

Data Destruction

20. BleachBit Replaces: Easy System Cleaner, standard file delete functions
This multi-function tool not only "shreds" deleted files, it also protects your privacy in a myriad of other ways like deleting cookies, erasing browsing history, deleting logs and cleaning up temp files. By getting rid of unwanted junk, it also helps speed your system and open up extra disk space. Operating System: Windows, Linux

21. Eraser Replaces: BCWipe Enterprise, standard file delete functions
When you simply "delete" a file from your drive, it can usually be recovered with forensic tools. However, Eraser uses tools approved by the Department of Defense to eliminate all traces of a file from your drive, protecting your privacy and preventing the spread of sensitive or classified information. Operating System: Windows

Desktop Publishing

22. Scribus Replaces: InDesign, QuarkXPress, Microsoft Office Publisher Scribus offers the advanced features professional graphic designers need along with an intuitive interface that anyone can master. With it, you can create press-ready output or PDFs of documents you plan to publish online. However, you should note that Scribus cannot convert files made with proprietary formats. Operating System: Windows, Linux, OS X

E-Commerce

23. Magento Replaces: Big Commerce, Volusion, NetSuite Ecommerce
Used by more than 100,000 merchants, including Office Max, Harbor Freight Tools, K-Swiss and others, eBay-owned Magento has been called "an emerging player to watch" by Forrester. In addition to the free community editions, it also comes in supported professional and enterprise editions, as well as a hosted turnkey version known as Magento Go. Operating System: Windows, Linux, OS X

24. osCommerce Replaces: Big Commerce, Volusion, NetSuite Ecommerce
Boasting a community 256,900 members strong, the award-winning osCommerce powers thousands of shops worldwide, including 12,700 that are linked on the site. More than 6,000 add-ons are also available to help you customize the software for your specific needs. Operating System: Windows, Linux, OS X

25. PrestaShop Replaces: Big Commerce, Volusion, NetSuite Ecommerce
One of the most popular eCommerce apps in Europe, PrestaShop boasts that it is used to open 30 new online stores every day. Paid support and training are available. Operating System: Windows, Linux, OS X

26. X-Cart Replaces: Big Commerce, Volusion, NetSuite Ecommerce
This feature-rich e-commerce solution touts itself as SEO-friendly, easy to customize, fast, secure and 100% PCI-DSS compliant. It comes in supported Gold and Pro editions, and hosting is also available from X-Cart. Operating System: Windows, Linux, OS X

E-mail/Collaboration/Groupware

27. Collabtive Replaces: Basecamp This Basecamp replacement tracks projects, milestones and tasks for small groups, and it even imports data from Basecamp. You can host it yourself or purchase hosting from Collabtive. Operating System: OS Independent.

28. EGroupware Replaces: Microsoft Office Outlook and SharePoint
This self-proclaimed "leading Online Collaboration Tool" combines e-mail, shared calendar, project management, content management and other collaboration capabilities into a single package. In addition to the community version, it also comes in supported on-premise and cloud-based versions. Operating System: OS Independent

29. Evolution Replaces: Microsoft Office Outlook
Sometimes called "the Outlook of Linux," Evolution offers e-mail, calendar, to-do list and contact management for the Gnome desktop. The interface should feel very familiar for anyone who's ever used Outlook. Operating System: Linux

30. Group-Office Replaces: Microsoft Office Outlook
Like Outlook, Group-Office features shared calendar and e-mail capabilities. In addition, it includes some basic project management, file sharing and CRM features. You can deploy server version on your own hardware (with or without paid support), or you can buy the SaaS version. Operating System: OS Independent

31. phpGroupWare Replaces: Microsoft Office Outlook, Sharepoint
This project includes more than 50 separate groupware apps that you can mix and match to suit your needs. Key features include e-mail, contact management, shared calendar, content management, project management, a bug tracker and more. Operating System: Windows, Linux

32. Thunderbird Replaces: Microsoft Office Outlook
Made by Mozilla, the organization best known for the Firefox browser, Thunderbird offers e-mail with a tabbed interface and excellent customization capabilities. If you would like to add calendar functionality, you'll need to download Mozilla's Lightning as well. Operating System: Windows, Linux, OS X

33. Zimbra Replaces: Microsoft Exchange
Zimbra's open source edition provides an alternative to Microsoft Exchange, with e-mail, shared calendar, contact and document management capabilities that can be accessed from a variety of desktop clients. The company also offers a free desktop client of its own, plus paid network or appliance versions. Operating System: Linux, Unix, OS X

Enterprise Resource Planning (ERP)

34. Apache OFBiz Replaces: NetSuite , Sage ERP
Apache's software suite for small businesses includes ERP, CRM, e-commerce, supply chain management, manufacturing resources planning, enterprise asset management and POS from a single solution. Apache does not provide support directly, but the site does list a number of third-party service providers who can assist with deployment and ongoing support needs. Operating System: OS Independent

35. Open ERP Replaces: SAP, Microsoft Dynamics For mid-size and larger enterprises, Open ERP offers more than 700 accounting, ERP and other business modules that can be tailored to a specific company's needs. Both a supported version and an online hosted version are also available with a monthly subscription. Operating System: Windows, Linux

36. Openbravo Replaces: SAP, Microsoft Dynamics
Used by more than 15,000 customers, Openbravo offers Web-based ERP capabilities, with a focus on agility and ROI. Besides the free community edition, it offers basic and professional versions which can be purchased through third-party partners. Operating System: OS Independent

37. ADempiere Replaces: SAP, Microsoft Dynamics
This community-run ERP project integrates well with Drupal and other open source projects to create a complete suite of business software. A wealth of documentation is available on the site, and the group also holds regular international conferences and training events. Operating System: Windows, Linux, OS X

File Transfer

38. FileZilla Replaces: CuteFTP, FTP Commander This project includes both an FTP server for Windows and a cross-platform FTP client. Both support FTP, FTPS and SFTP file transfer with an easy-to-use tabbed interface. Operating System: Windows, Linux, OS X

39. FireFTP Replaces: CuteFTP, FTP Commander
This Firefox add-on has been downloaded more than 22 million times. It allows you to download files via FTP or SFTP right from your browser window. Operating System: Windows, Linux, OS X

40. WinSCP Replaces: CuteFTP, FTP Commander
This award-winning FTP, SFTP, and SCP client comes with two different interfaces, so that you can pick the one that suits you best. Other notable features include an integrated text editor, authentication support, batch file scripting and more. Operating System: Windows

Financial Management

41. Buddi Replaces: Quicken
While it's not as full-featured as Quicken, Buddi is a simple, understandable personal finance program designed for people with little or no financial experience. It's Java-based, so it works on nearly all operating systems, and the website has tutorials available for new users. Operating System: OS Independent

42. KMyMoney Replaces: Quicken
This personal finance software from KDE features double-entry accounting and an intuitive GUI. The project's stated goal is "to be the best free software personal finance manager, period." Operating System: Windows, Linux, OS X

43. Money Manager Ex Replaces: Quicken
Another personal finance manager with an emphasis on simplicity, Money Manager Ex aims to offer "all the basic features that 90% of users would want to see in a personal finance application." Key capabilities include budgeting, one-click reporting, charts and graphs, depreciation tracking, AES encryption support, bill reminders and more. Operating System: Windows, Linux, OS X

44. TurboCASH Replaces: QuickBooks, Sage Accounting Software
This free, open source small business accounting package invites potential users to compare its features against those of its commercial competitors. It supports multiple languages, multiple currencies, multiple companies, batch data entry, VAT/tax reports and much more. Operating System: Windows

Games

45. 0 A.D. Replaces: Microsoft Age of Empires
Now in its eighth alpha release, 0 A.D. is a real-time civilization-building strategy game that plays a lot like Age of Empires. It offers excellent graphics, six different civilizations to play, and several multiplayer modes. Operating System: Linux, Windows, OS X

46. Alien Arena Replaces: Quake, Unreal Tournament
This self-described "furious frag fest" is a first-person shooter in the style of Quake III and Unreal Tournament. Boasting "one of the most active, loyal and committed communities of any free game in existence," Alien Arena has a large user base that makes it easy to find online competitors any time of day. Operating System: Linux, Windows, OS X

47. FlightGear Replaces: Microsoft Flight Simulator X
FlightGear describes itself as "sophisticated, professional, open source." It includes realistic graphics for more than 20,000 real world airports, 3 DVDs worth of accurate world scenery, several aircraft options and the ability to model your own aircraft. Operating System: Windows, Linux, OS X, others

48. FreeCiv Replaces: Civilization
Like many games in this genre, FreeCiv challenges players to manage a civilization from the Stone Age through the Space Age. The graphics and game play are fairly similar to Civilization I and II, but not as advanced as the more recent Civilization games. Operating System: Windows, Linux, OS X

49. Frets on Fire Replaces: Guitar Hero
Very similar to Guitar Hero, Frets on Fire lets you use your keyboard or a guitar controller to play along with tracks. This project has a huge community of users who have composed songs for the game, or you can import Guitar Hero tracks or your own songs. Operating System: Windows, Linux, OS X

50. Secret Maryo Chronicles Replaces: Mario Bros. Games
If you remember the old 2D Mario Bros. games fondly, you'll probably enjoy Secret Maryo Chronicles. It offers great old-school jump and run gameplay with plenty of levels. Operating System: Windows, Linux

51. StepMania Replaces: Dance Dance Revolution
This fun rhythm game works with your keyboards or dance pads (if you have them). You'll need to download songs separately from the game, but the site offers plenty of free songs. Operating System: Windows, Linux, OS X

Gateway Security Appliances

52. Endian Firewall Community Replaces: Check Point Security Gateways, McAfee Total Protection, SonicWall Appliances, others
With the Endian Community version, you can create your own network security appliance using an older PC. It offers firewall, antivirus, spam blocking, content filtering, a VPN and other security capabilities in a single package. Pre-configured hardware appliances and commercially supported software appliances are also available at the site. Operating System: Linux

53. Untangle Replaces: Check Point Security Gateways, McAfee Total Protection, SonicWall Appliances, others
Much like Endian, Untangle offers an integrated security appliance that you can deploy on your own hardware, or you can purchase a pre-configured hardware appliance from the company. Untangle also has a network of third-party partners who offer Untangle-based products and services. Operating System: Windows, Linux

Graphics/Drawing

54. Dia Replaces: Visio
"Roughly inspired by Visio," Dia is perfect for creating org charts, network diagrams, flowcharts, and other simple diagrams. It saves XML files, or it can export to EPS, SVG, XFIG, WMF and PNG formats. Operating System: Windows, Linux/Unix

55. Gimp Replaces: Photoshop
There's no need to spend hundreds of dollars on Photoshop when Gimp offers the same features for free. It includes a full range of features, from photo re-touching capabilities for amateur photographers to advanced layers and photo manipulation tools for professional graphic designers. For the Windows version, see Gimp-win. Operating System: Windows, Linux

56. Inkscape Replaces: Illustrator, CorelDraw
Much like Illustrator and CorelDraw, Inkscape allows you to create, edit and save vector graphics. It provides a whole host of advanced features in a streamlined, intuitive interface. The website also offers lots of support and documentation, as well as a library of free clip art you can use in your creations. Operating System: Windows, Linux, OS X

Instant Messaging

57. Adium Replaces:AIM, Yahoo! Messenger, Windows Live Messenger
Very similar to Pidgin (see below), this Mac-only software allows users to connect to multiple networks at once, including AIM, MSN, Jabber, Yahoo, and others. It offers a tabbed interface, and it integrates with your Address Book. Operating System: OS X

58. aMSN Replaces:Windows Live Messenger
Designed to replace MSN Messenger (now known as Windows Live Messenger), aMSN is a skinnable client that works with Microsoft's IM network only. Noteworthy features include offline messaging, voice clips, custom emoticons, group support, multi-language support, webcam support, tabbed windows, display pictures and more. Operating System: Windows, Linux, OS X

59. Pidgin Replaces:AIM, Yahoo! Messenger, Windows Live Messenger
This very popular open source IM clients connects with up to 16 different chat networks simultaneously. It supports file transfers, away messages, buddy icons, custom emoticons and typing notifications, and it has a large library of plug-ins that extend its capabilities further. Operating System: Windows, Linux/Unix

Office Productivity

60. AbiWord Replaces: Microsoft Word
Similar to older versions of Word, AbiWord reads and writes most word processing document formats, including OpenOffice and Word formats. The latest version adds a lot of collaboration capabilities, and it integrates tightly with the free AbiCollab.net service which allows users to store and edit documents in the cloud. Operating System: Windows, Linux, OS X, others

61. FreeMind Replaces: MindJet
This open source mind mapper makes it easy to display the links between ideas. It's great for making outlines, brainstorming, making notes and more. Operating System: OS Independent

62. Gnumeric Replaces: Microsoft Excel
Gnumeric describes itself as "free, fast and accurate," and an outside reviewer has praised it as more accurate than its commercial competitors. It opens files from most other popular spreadsheet programs (including Excel and Lotus), and it offers 583 different functions, including 194 you can only find in Gnumeric. Operating System: Windows, Linux

63. KOffice Replaces: Microsoft Office
KDE's office productivity suite includes the KWord word processor, KCells spreadsheet, Showcase presentations, Kivio diagrams and flowcharts, and the Artwork vector drawing program. The interfaces are intuitive but significantly different than Microsoft Office, so they take a little getting used to. Operating System: Windows, Linux

64. LibreOffice Replaces: Microsoft Office
When Oracle took over OpenOffice.org (see below), a group started this fork to continue community development. It offers all the same great features and capabilities of OpenOffice.org, plus a few improvements all its own. Operating System: Windows, Linux, OS X

65. NeoOffice Replaces: Microsoft Office
Also very similar to OpenOffice.org (see below), NeoOffice offers an interface and features tailored for Mac users. The latest update supports Mac's versions, full-screen mode and resume features. Operating System: OS X

66. OpenOffice.org Replaces: Microsoft Office
Now an Apache project, OpenOffice.org includes Microsoft-compatible word processing, spreadsheets, presentations, graphics and database software. At twenty years old, it's a mature project with all of the advanced capabilities and stability that home or business users need. Operating System: Windows, Linux, OS X, others

Operating System

67. Linux Mint Replaces: Windows
The fourth most popular home operating system, Linux Mint offers great ease of use for those new to Linux. It's based on Debian and Ubuntu and comes with a library of 30,000 free software applications.

68. Red Hat Replaces: Windows
Probably the best known flavor of Linux, Red Hat comes in desktop and server versions that are suitable for enterprise users. Red Hat's software requires a paid support contract, or you can download the community version for free from Fedora.

69. SUSE Replaces: Windows
Like Red Hat, SUSE is designed for enterprise users and requires a support contract. However, also like Red Hat, a free community version is available through openSUSE.

70. Ubuntu Replaces: Windows
Suitable both for enterprise and home users, this extremely popular Linux distributions comes in desktop, server and cloud versions and now a TV version. It boasts 20 million users and offers fast performance, a stylish interface, ease of use and good security.

Password Manager

71. KeePass Replaces: RoboForm, LastPass
With KeePass, you no longer have to remember lots of different passwords. Instead, you'll only need to keep track of one master password, while KeePass stores your very strong passwords in an encrypted database. Operating System: Windows

PDF Tools

72. PDFCreator Replaces: Adobe Acrobat
Adobe's Acrobat software is expensive, but you don't actually need that software to create PDFs. PDFCreator can write PDF files from any application capable of printing, and it includes features like encryption, digital signatures and more. Operating System: Windows

73. Sumatra PDF Replaces: Adobe Reader
The free Adobe software isn't your only option for reading PDF files. The Sumatra PDF reader offers similar functionality with a lighter footprint for faster performance. Operating System: Windows

POS

74. Floreant POS Replaces: QuickBooks Point of Sale, AccuPOS
For restaurants only, this POS system works with touch screens and handles operations like split checks, kitchen print, drawer pull, tax, discounts and more. Its list of users includes the Denny's chain in New York. Operating System: OS Independent

75. Lemon POS Replaces: QuickBooks Point of Sale, AccuPOS
Best for small or very small businesses, this Linux-based point of sale system offers features like role-based permissions, support for multiple terminals, sales suspension, custom orders and more. It stores all inventory data in a MySQL database and boasts excellent security. Operating System: Linux

Project Management

76. OpenProj Replaces: Microsoft Project
Very similar to Microsoft Project, this popular app lets you assign resources, schedule tasks and handle the other aspects of managing an ongoing project. It also imports and exports Microsoft Project files. However, note that the export to PDF function in the software is shareware, not open source. Operating System: Windows, Linux, Unix, OS X.

77. GanttProject Replaces: Microsoft Project
Similar to OpenProj, GanttProject can also import and export data from Microsoft Project. Other key capabilities include Gantt charts, PERT charts and collaboration features. Operating System: Windows, Linux, OS X.

Security

78. ClamAV Replaces: Avast! Linux Edition, VirusScan Enterprise for Linux
The "de facto standard for mail gateway scanning," ClamAV is a set of command line tools for protecting networks from malware. The same software is also available for the Windows desktop through a paid program called Immunet that can be downloaded from the same site. Operating System: Linux

79. ClamWin Replaces: Kaspersky Anti-Virus, McAfee AntiVirus Plus
For an open source version of ClamAV for Windows, try ClamWin. It boasts more than 600,000 users and integrates with Windows Explorer and Outlook. Operating System: Windows

School Management and E-Learning

80. Claroline Replaces: Blackboard, eCollege/Pearson Learning Studio,Articulate, TrainCaster LMS
Used by educational institutions and enterprises in 93 countries, Claroline includes tools for writing online course descriptions, delivering online course content, creating exercises, maintaining wikis, publishing announcements and more. It's won numerous awards, and it's available in 35 different languages. Operating System: Windows, Linux, OS X

81. Moodle Replaces: Blackboard, eCollege/Pearson Learning Studio,Articulate, TrainCaster LMS
More than 73,000 sites have registered their versions of Moodle, and they offer nearly 6 million online classes that reach more than 58 million students. It's a full-featured e-learning platform that aims to give educators "the best tools to manage and promote learning." Operating System: Windows, Linux, OS X

82. openSIS Replaces: PowerSchool
School budgets are getting tight, and openSIS saves most schools about 75 percent compared to commercial alternatives. It's reliable, scalable, and includes most of the features you would find in software like PowerSchool. In addition to the free community version that's suitable for smaller schools, it also comes in commercially supported school and district editions. Operating System: Windows

83. SchoolTool Replaces: PowerSchool
Designed for schools in the developing world, this student information system offers a Web-based system for tracking attendance, grades, demographics and more. It runs on a Ubuntu Linux server, and can also be deployed in the cloud. Operating System: Linux

Small Business Server

84. ClearOS Replaces: Microsoft Small Business Server
This multi-function server software includes anti-malware, anti-spam, mail server, content filter, stateful firewall, VPN, WAN, file and print sharing, groupware, Web filter and other capabilities. In addition, paid support, pre-configured hardware and other services are available from ClearSDN. Operating System: Linux

85.Zentyal Replaces: Microsoft Small Business Server
Like ClearOS, Zentyal can serve as a gateway, infrastructure manager, unified threat manager, office server and/or unified communication server. Subscriptions, support, training, add-ons and other services are available for a fee. Operating System: Linux

Video Tools

86. Cinelerra Replaces: Adobe Premiere
Describing itself as "the same kind of editing suite that the big boys use," Cinelerra encourages users to "unleash the 50,000 watt flamethrower of content creation in your UNIX box." Note that a community fork of the project can be found atCinelerra.org. Operating System: Linux

87. OpenShot Video Editor Replaces: Adobe Premiere
This video editor is very popular with Linux users and has been frequently featured in various Linux-related magazines. Key features include compositing, overlays, 3D animated titles, unlimited tracks and layers, scrolling credits, rotoscoping support, digital zoom and much more. Operating System: Linux

88. VLC Media Player Replaces: Windows Media Player
This cross-platform player supports most multimedia files as well as DVD, Blu-Ray, Audio CD, VCD, and various streaming protocols. It's simple, powerful, fast and very popular with open source aficionados. Operating System: Windows, Linux, OS X, others

89. XBMC Media Center Replaces: Windows Media Player
Designed for home theater PCs (HTPCs), this award-wining multimedia player also plays most types of files. It also supports most remote controls, and it automatically creates a personal library of your audio and video files. Operating System: Windows, Linux, OS X.

Web Filtering

90. DansGuardian Replaces: McAfee Family Protection NetNanny
Award-winning DansGuardian uses phrase matching, PICS filtering, URL filtering to block objectionable content on your network. Note that this is not software for protecting an individual PC—to use it, you need a server. Operating System: Linux, OS X

Web Site Creation

91. BlueGriffon Replaces: Adobe Dreamweaver, Microsoft Expression Web
One of the younger projects on our list, BlueGriffon offers a WYSIWYG Web editor powered by the same Gecko engine that runs Firefox. It offers an intuitive interface for building sites that conform to the latest Web standards. Operating System: Windows, Linux, OS X

92. KompoZer Replaces: Adobe Dreamweaver, Microsoft Expression Web
With an interface very similar to what you'll find on Dreamweaver, KompoZer makes it easy for anyone to create Web pages, even if you don't have a lot of technical knowledge. Key features include a WYSIWYG editor, integrated file management via FTP, HTML mode, tabbed editing, forms support and more. Operating System: Windows, Linux, OS X