In 2001, it was an uphill battle for Sourcefire to find financiers.
The new technology company had developed free network security software using open-source methods, meaning, essentially, that it was created and modified by an online community of public volunteers and that anyone could access its source code.
Such development went against traditional corporate thinking, which advises that intellectual property be kept close to the vest, protected by patents and accessible only when purchased.
And it scared investors.
"Back then, it was a very hard sell," said Sourcefire spokeswoman Michele Perry.
But times have changed. At an open-source conference in San Francisco this year, established technology companies that once disparaged such open access now promoted it.
The government of Massachusetts began converting to open-source document technology this year. And last month, Microsoft, which has long criticized "OS," launched a Web site devoted to it.
"Now it's almost the opposite, it's a strength," said Perry, whose Columbia company went public in March at a share price higher than predicted. Its original product, called Snort, has been downloaded more than 3 million times.
By the time the term open source was coined at a conference in 1998, the practice was already decades old and had an established culture of users on the business fringe.
They often pitted themselves against big corporations (Microsoft in particular), considered themselves somewhat underground and were not afraid to show disdain for the proprietary way of doing things.
Nearly a decade later, however, open source has gone mainstream and its principles have become almost conventional in today's World Wide Web.
The current nature of the Internet is a grass-roots kind of place, where regular people drive the content. Consumers post product reviews on commercial sites, volunteer enthusiasts control encyclopedia entries on Wikipedia, amateur film makers post videos on YouTube and thousands of others blog or maintain personal profiles on sites such as MySpace.
It is the right environment for open source to take off, technology analysts say.
Market researcher Gartner Inc. is predicting that open source will "restructure" the software world.
Analysts at IDC, a Massachusetts technology consulting company, are calling it "the most significant all-encompassing and long-term trend that the software industry has seen since the early 1980s."
Open-source products are used by three-quarters of the world's organizations, and hundreds of thousands of open-source projects are in the works.
"The perspective of the open-source software model as an IT counter culture movement is quickly becoming outdated as more markets increasingly incorporate open source into mainstream IT solutions," Gartner analyst Mark Driver wrote in a report last spring.
Proponents say open-source development leads to better, less-expensive technology because it is often vetted by multiple programmers around the world, many of them hobbyists who thrive on the rush of improving a product, finding its bugs or manipulating source code to create other offerings.
They also claim the software end products are more secure because of that, with many people looking for holes and proposing patches to them. It is akin to making a super strong safe.
Even if burglars know how a safe was made, they won't be able to crack it if there aren't vulnerabilities to exploit. If the safe is relatively weak, it is more likely to be compromised even if its blueprint is hidden.
Both the National Security Agency and the Defense Department guard their networks with open-source security software.
The community style of development is not immune to being abused, however, as Wikipedia found out in 2005. The online encyclopedia, which is written and edited by volunteers, got into trouble after a contributor posted a false entry maligning journalist John Seigenthaler Sr.
Those who question open-source development - often the large, established software companies - have also said it leads to clunky, overwritten software and devalues what programmers do because they are not paid.
They also say open source makes a mess of revenue models, because much open-source software is free. And, as Roger Novak of Novak Biddle Venture Partners in Bethesda says, "Free is not something you can make money on."
There are three main business models for open-source companies. In one, the software is free, but support services are not. In the second, the software is free, but upgraded versions are not. And in the third, companies sell hardware that comes bundled with free open-source software that makes it work.
"We see a number of opportunities [in open-source companies]," Novak said, "But again, we sort of approach them with, I won't call it a jaundiced eye, but we really have to understand the business model that will make this a significant company."
Novak's firm has invested in Trusted Computer Solutions, a Virginia company building on open-source technology developed by Red Hat Inc., making it more secure.
The products already are used by the U.S. government, and the company launched its first commercial product last week.
In Annapolis, two-year-old open-source company Zenoss Inc. gives its basic network monitoring technology away, but it sells support services and upgraded versions of the software.
Among its customers is Baltimore's Mercy Medical Center, which was looking for a better way to keep tabs on its networks and more than 200 servers and applications.
Mercy had piecemeal software in place, but nothing that could monitor for mishaps systemwide.
More often than not, doctors and nurses would be the ones to alert the information technology department to blips, rather than monitoring technology, said Chief Information Officer Jim Stalder. So he went in search of a solution about a year and a half ago.
"We started to look at proprietary stuff initially, then once the quotes came back, we saw for the most part, they were extremely high-priced. That was more functionality than we needed," Stalder said. "[Zenoss' software] was less expensive, met our needs and really allowed us the flexibility to customize it should we need to in the future."
Zenoss' information technology monitoring software is available on SourceForge.net, an open-source clearinghouse.
Thousands have downloaded Zenoss' software, talked about it on forums and offered new ideas. It is consistently among the top 10 most active open-source projects on the Web site, which has more than 1 million registered users and more than 100,000 projects online.
Zenoss co-founder Bill Karpovich said his goal is to provide simple and affordable IT management tools that have a "positive impact on the world."
It is a philosophy he developed after burning out in the corporate world and quitting his job at USinternetworking in 2002, then indulging in a year of reflection.
He studied religion and philosophy, spent weeks in Thailand, read dozens of books, looked after sheep in France, fished the Chesapeake Bay and pondered the world. When he was ready to go back to work, it was on new terms, Zen terms - open source terms.
He refers to the style of development as a religion of sorts, one grounded in Zen principles of simplicity and awareness.
His company name stands for the "Zen of Open Source," and its mission is to do things better, faster and cheaper than the traditional way. "[Open source] is really changing software," he said. "It's really hard to compete with an army of volunteers."
A style of software development in which the source code (basically the technology's blueprint) is publicly accessible. Programming enthusiasts are encouraged to review and alter the code to create better or derivative products.