Software maker Novell has been allowed to proceed with a long-running antitrust lawsuit against Microsoft after an appeals court reversed a lower court's summary judgement in favor of Redmond.

Novell claimed that its operating system products and several of its software applications were unfairly squeezed out of the market by Microsoft in the 1990s. In 1996 Novell assigning rights to sue Microsoft to a separate company called Caldera.  Caldera receiving a $280 million settlement four years later.

However in 2004, Novell sued Microsoft in its own right, claiming its WordPerfect word processing application was the victim of unfair competition by Microsoft. Last year, Microsoft lawyers convinced a Judge that Novell's claims were subject to the 1996 agreement with Caldera, which relinquished the right to sue Microsoft. The appeals court reversed that judgement saying that the previous agreement with Caldera covered a different set of products.