Upcoming open source companies have grown

6. rPath

Why it made the list: Server virtualization is paving the way for simpler application deployments, in which an operating system and application can be packaged and deployed in a virtual machine for flexibility. VMware has begun offering preconfigured, prepackaged application appliances, but rPath provides an open source foundation for independent software vendors (ISV) to use in creating these appliances. Enterprise users should be watching and pushing their ISVs to take this approach, because such application appliances mean the end of complex, multicomponent application deployments.

Highlights from the past year: rPath's platform for creating and maintaining software and virtual appliances has been downloaded 1 million times as of July 31, and was named "most innovative software idea" at a Computing Technology Industry Association conference this summer.

7. Sahana

Why it made the list: The Sahana Project -- a secure Web portal that includes applications used to coordinate and collaborate during relief efforts following disasters -- illustrates the humanitarian benefit of open source: It can be useful to large organizations dealing with the aftermath of disasters.

Highlights from the past year: Sahana won the Free Software Foundation Award for Projects of Social Benefit in March, beating out finalists Project Gutenberg and One Laptop Per Child.

8. WSO2

Why it made the list: Most existing middleware was designed to handle transaction-heavy, Java-based applications, so Web-services capabilities had to be layered on top. WSO2 is building its middleware specifically for Web services and using an open source model to encourage community involvement in its development.

Highlights from the past year: WSO2 rolled out an enterprise service bus in June to help businesses manage Web services and service-oriented architectures.

9. Zenoss

Why it made the list: Zenoss provides a management package that lets users manage and monitor everything from network devices to servers to applications to environmental conditions. The free software should be of interest to midsize companies, which haven't had access to these capabilities in the past because of cost issues.

Highlights from the past year: Zenoss got the highest marks among three open source management products evaluated in comparative reviews by Network World's Clear Choice Test in June. Zenoss earned higher marks than Hyperic and GroundWork Monitor for providing excellent discovery of network resources and an intuitive user interface.

10. Zmanda

Why it made the list: By basing its products on open source software, Zmanda can offer a cost-effective data protection alternative to costly proprietary offerings from such companies as EMC.

Highlights from the past year: Zmanda secured US$8 million in funding in May. The previous month, the vendor released a Zmanda Recovery Manager backup and recovery solution designed specifically for the open source database MySQL.