Entrepreneurs attending a forum in Germany this week showed how they plan to use clever open-source products\u2014commercially\u2014to compete with proprietary software companies.The Open Source Forum gave software entrepreneurs from Europe and the United States\u00a0an opportunity to present their business ideas to venture capitalists and other IT experts. Their message was loud and clear: Open source is a disruptive technology that is here to stay, and it will nibble, or maybe even someday gobble, away at the customer base of big and pricey commercial software companies.The forum, the first of its kind in Germany, took place earlier this week in Potsdam, near Berlin. It was hosted by the Hasso Plattner Institute for Software Systems Engineering, IBM and Deutsche Telekom. Hasso Plattner became a billionaire selling commercial software at SAP, a company he cofounded.Among the ventures was XenSource, founded and run by the original team that developed the Xen secure virtualization technology. The team brought the technology to the open-source community in 2003.With Xen virtualization, a thin software layer known as the Xen hypervisor is inserted between the server\u2019s hardware and operating system. The hypervisor provides an abstraction layer that allows each physical server to run one or more virtual servers, effectively decoupling the operating system and its applications from the underlying physical server. XenSource offers a free "community" product and a commercial product, XenEnterprise. "Many big companies are interested in virtualization today, and they\u2019re particularly interested in our open-source approach because that lets them better see what\u2019s going on inside this technology," said XenSource Chief Architect Steve Hand.Mindquarry is a German startup founded by three former students of the Hasso Plattner Institute for Software Systems Engineering in Potsdam. The company has developed an open-source collaboration system. It allows users to, for instance, edit documents simultaneously, communicate via e-mail, instant messaging or real-world meetings, and search for information through a range of channels. Mindquarry plans to offer its first product in February, according to cofounder and Chief Executive Officer Lars Trieloff.SeeWhy Software is a U.K. company that has used open-source technology to develop a real-time business intelligence software system. Like many venture capital-funded startups, SeeWhy offers a free and commercial product. SeeWhy has embraced the open-development approach of the open-source community because, as the company\u2019s cofounder and Chief Executive Officer Charles Nicholls put it, "We\u2019re brave enough to realize that we can\u2019t get everything right on our own." JasperSoft is a San Francisco startup that also offers open-source-based business intelligence products, including its new on-demand Jasper4Salesforce. "There are a lot of BI products out there, but many of them are targeted at big customers," said Don Wight, vice president of worldwide field operations at open-source business intelligence software vendor JasperSoft. "We\u2019re talking about low-cost BI for the masses."-John Blau, IDG News Service (Dusseldorf Bureau)Related Links:\n\nOpen-Source Ventures: Where\u2019s the Money?\n\nEuropean Governments Back Open Source\n\nThe Open Source (CIO.com blog)\n\nThe Myths of Open SourceCheck out our CIO News Alerts and Tech Informer pages for more updated news coverage.