Before we go any farther, we should define what we mean by "commercial open source software." As with many topics in the open source world, different people have very different opinions about what that phrase means.
Some argue that if an open source project has a commercial side it's not truly open source any more. Others hold that if you look hard enough, all open source software has some sort of commercial motive.
On this list, you'll find a variety of projects that are based on open source code and whose owners make money directly from their software. How they make that money varies: Many of the projects on the list have a "community" version that is available under an open source license and "professional" and/or "enterprise" versions that add features that are only available with a commercial, paid license.
Other projects offer the software for free, but require payment for support, maintenance, installation or other services. A few others charge for hardware products based on the software. And a growing group of organizations make money by hosting their open source software on a software-as-a-service (SaaS) basis.
This list doesn't include projects that simply request donations or those that make money only by selling hats, T-shirts and other gear emblazoned with their logo. We also left off projects that offered paid support as an afterthought or those with support and services available only from third parties.
Why put together a list of commercial open source projects at all? Many businesses find it preferable to acquire software under a commercial license because they are worried about some of the legal provisions of some open source licenses, particularly the GPL. In addition, many companies want reliable support and maintenance for their software and are willing to pay for it.
Home users are much less likely to pay for open source software, and as a result, the vast majority of the projects on this list are aimed at businesses rather than home users.
As always, if you would like to suggest a project that you think should be on our list, feel free to mention it in the comments section below.
This software for ISPs, telecoms, ASPs, media, software developers and other firms who charge for subscription services offers a highly scalable, robust and flexible Web-based billing solution. The complete software is available for free; support and other services are available for a fee. Operating System: OS Independent.
Used by more than 45,000 companies and downloaded more than 400 times a day, Palo adds online analytical processing capabilities to Microsoft Excel. It's available in either a community or a premium version, which includes more features and support. Operating System: OS Independent.
The "open source business intelligence leader," Pentaho offers enterprises the opportunity to cut their BI licensing costs by 90 percent. In addition to the free community edition, it's available in a variety of paid versions, including an on-demand SaaS version. Operating System: Windows, Linux, OS X.
This Web-based reporting tool boasts an open architecture, ease of use, and powerful reporting capabilities. It's available in an open source version or in a professional version. Operating System: OS Independent.
"The world-leading open-source system for data and text mining," RapidMiner combines Data Integration, Analytical ETL, Data Analysis, and Reporting in a single solution. The enterprise versions offer an extended list of features, professional support and maintenance. Operating System: OS Independent.
Java-based Bonita Open Solution consists of three separate parts: a process modeling tool, a BPM and workflow engine, and the user interface. The full version of the software is free, with training and three different levels of support available for a fee. Operating System: OS Independent.
Available in open source, enterprise, or cloud editions, ProcessMaker helps companies like Toyota, Lenovo and Honeywell simplify and optimize workflows. It allows companies to reduce their paperwork, become more efficient and improve outcomes. Operating System: Windows, Linux.
Cloud.com provides CloudStack on an infrastructure-as-a-service (IaaS) basis to companies that want to build and deploy private clouds. While the community version of the software is available under a GPL license, the enterprise and service provider editions include some proprietary code. Operating System: Linux.
Similar to (but much less expensive than) RightScale, this open source cloud computing platform makes it easier to scale Web sites and Web apps up and down as needed. The development edition is available for free for those with one server farm and up to eight servers. Production and mission critical subscriptions are available for those with larger needs. Operating System: Linux.
Alfresco's open source solution offers document management, Web content management and collaboration features. It's commercial products add some records management features as well as enterprise-grade support. Operating System: Windows, Linux, OS X.
Recently named the "most popular Java CMS," Liferay offers portal, publishing, content management and collaboration solutions. Well-known users include Cisco, Sesame Street, T-Mobile, Barclays and others. It offers both an open source and a supported enterprise version of its software. Operating System: OS Independent.
Like many of the other items on this list, this enterprise-focused Web content management software comes in a free open source version or a paid enterprise edition. The latest update offers excellent collaboration features, including concurrent editing, comparing revisions, deletion workflow, and content translation. Operating System: Windows, Linux.
With companies like HTC, the Washington Post, HP, Novell, Autodesk and others as clients, MindTouch claims that it "makes the world's most respected social knowledge base." The MindTouch Core product is available with an open source license, while a commercially licensed version is available in on-premise or hosted versions. Operating System: Windows, Linux.