Alacritech said on Wednesday that the injunction blocks Microsoft from using its Chimney architecture, which Alacritech said Microsoft plans to include in both a "scalable networking pack" for Windows Server 2003 and in Longhorn, the next version of Windows.
Microsoft's Chimney software provides support for hardware that accelerates networking using the TCP/IP standard, which underlies the Internet and countless private networks. Microsoft designed Chimney to minimise compatibility issues with existing computing technology.
"After Alacritech discovered that Microsoft Chimney is based on intellectual property that we developed, patented and own, we offered Microsoft a licence," Alacritech chief executive Larry Boucher said in a statement. "Microsoft rejected licensing terms that would be acceptable to us. We were forced to sue Microsoft to stop them from continuing to infringe, and inducing others to infringe, on our intellectual property rights."
Microsoft spokeswoman Stacy Drake reiterated the company's position that its Chimney technology was "independently developed."
"As an intellectual property company, we invest heavily in research and development and are committed to respecting the intellectual property rights of others," Drake said.
Alacritech sued Microsoft last August, alleging that Chimney infringes on two Alacritech patents, both titled "protocol processing stack for use with intelligent network interface device."
According to Alacritech, Microsoft first discussed plans for Chimney at a hardware conference in the spring of 2003. Alacritech said it offered to license its technology to Microsoft that October, but was rebuffed in April 2004, prompting it to file its suit.
An Alacritech representative declined to comment beyond the company's press release.