Vertical Computer Systems is suing Microsoft for patent infringement related to Microsoft's .Net platform.

Vertical filed suit 18 April in a US District Court in Texas alleging that Microsoft has infringed on its Patent No. 6,826,744, for a "system and method for generating websites in an arbitrary object framework".

The patent is for Vertical's SiteFlash technology, which utilizes Extensible Markup Language (XML) to create a component-based structure to build and efficiently operate Web sites, according to the company's website. A Vertical spokesman could not be reached for comment.

The complaint says Microsoft is still willfully infringing on the patent despite Vertical having put Microsoft on notice about it on 7 February. Vertical is asking for a jury trial.

Vertical, based in Texas, describes itself as a global web services provider. It went public in 2000 but is not listed on a major stock exchange.

A Microsoft representative was not immediately available for comment.