Apple has been slammed with four patent abuse lawsuits from

The legal actions - repsonses to an outstanding action against filed by Apple - were filed in Federal District Court in San Francisco on Monday, April 17.

Burst alleges that the iTunes Music Store, iTunes software, iPods and Apple's QuickTime Streaming products infringe Burst's US Patents 4,963,995; 5,995,705; 5,057,932 and 5,164,839.

Burst's filing responds to a suit that Apple filed against Burst in January of this year, seeking a declaration that Burst's patents are invalid and that Apple does not infringe them.

Burst wants Apple to pay a reasonable royalty for its infringing products and services, and also seeks an injunction against further infringement. is represented in the action against Apple by San Francisco law firm Hosie McArthur, who also represented Burst in its successful litigation against Microsoft. In March 2005, Microsoft settled that litigation by paying Burst $60 million for a non-exclusive license to Burst's patents.

Burst has also expanded its legal team in the Apple litigation to include attorneys from the Seattle office of Susman Godfrey, as well as Houston-based intellectual property firm Heim, Payne & Chorush. Also representing Burst is Palo Alto-based intellectual property firm Carr & Ferrell.

While saying he’d rather not use the courts, chairman & CEO Richard Lang described his company’s technology as “essential” to Apple's success, providing it with a critical audio and video-on-demand media delivery solution. According to Lang, "We have a responsibility to protect our patents and to seek a fair return for the many years and tremendous investment that we have made in developing Burst technology and patents."

Apple did not license Burst's technology when it introduced its iPod and iTunes products in 2002. Lang speculates that Apple may have assumed that Burst's patents would be invalidated in Microsoft's defence of the then-pending litigation. Instead, Microsoft licensed Burst's patents.