The move was a rare one for Microsoft. Although the company is often the target of patent litigation, it's rarely the instigator. In Microsoft's , it's accused others of infringing its patents only three times before today.
The last time was in 2009 when it over the company's in-car navigational devices.
The other patent infringement lawsuits Microsoft initiated were against Taiwanese mouse maker Primax Electronics in 2008, and peripherals manufacturer Belkin in 2006. Microsoft settled with both companies before the lawsuits reached trial.
"They don't sue often," said Rob Enderle, an analyst at Enderle Group. "It's very rare that they aggressively go after someone [on patents]. But these are core Microsoft patents, the company's crown jewels. They'll heavily defend these against any software developer."
According to Microsoft's complaint, which was filed on Tuesday in a Seattle federal court, Salesforce.com is using Microsoft-patented technologies in its Web-based CRM software and service service, and in supporting hardware and software.
Among the patents are several that at a glance appear to be quite broad. One of the nine patents that Microsoft alleged Salesforce.com infringed is entitled "System and method for providing and displaying a web page having an embedded menu," while another is labeled "Method and system for stacking toolbars in a computer display."
"Maybe Salesforce was betting that they're too general [for Microsoft] to defend," said Enderle. "Older patents especially are sometimes hard to defend because they're so general. We'll see."
Salesforce.com's director of public relations, Gordon Evans, declined to comment on the lawsuit today.
Microsoft had no such hesitation. "Microsoft has been a leader and innovator in the software industry for decades and continues to invest billions of dollars each year in bringing great software products and services to market," said Horacio Gutierrez, Microsoft's deputy counsel of intellectual property and licensing, in a statement.
"We have a responsibility to our customers, partners, and shareholders to safeguard that investment, and therefore cannot stand idly by when others infringe our IP rights," Gutierrez said.
"My best guess is that Salesforce thought Microsoft was all bark and no bite," said Enderle. "But these patents are the building blocks of Microsoft, and differentiate its products from others'," he said.
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld . Follow Gregg on Twitter at @gkeizer or subscribe to Gregg's RSS feed . His e-mail address is gkeizer@ix.netcom.com .
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