Microsoft might have to delay shipment of an upgrade to Windows Server 2003 and the company's next major operating system, Longhorn, as a result of an injunction made by a U.S. District Court in response to claims by Alacritech, a start-up company, that Microsoft appropriated its technology without a license. The preliminary ruling prevents Microsoft from using its TCP offload architecture -- code-named Chimney -- that it has included in its Windows Server 2003 and Longhorn. According to Alacritech, it met with Microsoft in 1998 and described its architecture in detail under a nondisclosure agreement. In April 1999, it delivered to Microsoft a detailed architecture document for integrating SLIC technology into the Windows operating system. In June, Alacritech said, Microsoft cut off communication with the firm. "After Alacritech discovered that Microsoft Chimney is based on intellectual property that we developed, patented and own, we offered Microsoft a license," said Larry Boucher, president and CEO, Alacritech. "Microsoft rejected licensing terms that would be acceptable to us." The company then sued Microsoft in Federal District Court in August 11, 2004, alleging that Chimney is based on technology that it began patenting in 1997. Microsoft has claimed that it developed Chimney independently.