Judging by the reaction to Microsoft's patent assertions, open source advocates have been put on the defensive. But Rod Johnson, the developer of the popular Java framework, Spring, hasn't been thrown for a loss. "Open source is entrenched. Customers and software companies have too much at stake" to be swayed by Microsoft's saber rattling, he says.

Johnson is somewhat outside the debate that's been going on since Microsoft stated that it believes 235 of its patents are infringed by various pieces of open source code. The Spring framework is not a Linux based product. It simplifies the development of Java applications and provides the underlying plumbing, such as connections to Web services, to make development easier.

"I'm not an expert on the Linux space," he wrote in an email message, responding to an Information Week query. But open source code "should not be equated with intellectual property theft," he said. Many open source projects lead their commercial counterparts in innovations, such as the Apache Web server. If their commercial competitors then steal or match their ideas it's not viewed as theft because open source code developers make no attempt to patent their software.

Johnson also says he has no special insight into what Microsoft is up to, but he doesn't think it matters all that much. It won't change attitudes toward open source adoption.

"Customers have long since decided open source is safe to use. In our space, it is hard to find any enterprise customer that does not use a lot of open source," he noted. Leading closed source products from IBM, BEA and Oracle use Apache, Samba and other open source internally, he added.

Microsoft, he conceded, "is threatening a nuclear strike, which could have unpredictable consequences for everyone… Some software patents that have been granted are ridiculously vague or cover concepts that clearly have been anticipated [in previous products].

"If all the big vendors tried to enforce all their patents, the software industry would shut down and the courts would come to a standstill," he said. Open source code projects, in that sense, are an easy target because they haven't accumulated their own patent defense arsenal.

But he's also seen Microsoft take positive steps toward engagement with open source projects, which doesn't make sense if it wants to shut down such activity. On one hand it maintains a bold front on patents, while building as many ties as possible to open source behind the scenes.

"I doubt that Microsoft wants to plunge the industry into a nuclear winter," he concluded.

In addition to heading the Spring open source project, Johnson is CEO of the company behind Spring, Interface21, which just received $10 million in funding from Benchmark Capital.