Updated

As the legal case against BlackBerry maker Research In Motion drags on, RIM's competitors have begun to turn their litigious attention on each other.

Visto on Jan. 31 announced that it is suing Good Technology for patent infringement.

The suit, alleging infringement of four wireless e-mail patents held by Visto, was filed in the U.S. District Court in the Eastern District of Texas.

The suit alleges that several of Good's products, including Good's signature GoodLink push e-mail server, infringe on Visto's patents.

"Visto's commitment to providing our customers with world-class remote e-mail and data access services depends on our ability to protect the intellectual property that we worked tirelessly to develop almost a decade ago," said Brian Bogosian, chairman and CEO of Visto, in a statement.

Good officials declined to comment.

This suit follows a suit that Visto filed against Microsoft on Dec. 15, alleging that Microsoft's Windows Mobile 5.0 operating system also infringed on Visto's patents.

Meanwhile, on Dec. 14, Visto signed a technology licensing agreement with NTP, the patent-holding company suing RIM for patent infringement.

NTP also has licensing agreements with Good, and holds stakes in both Good and Visto.

NTP sued RIM for alleged patent infringement on nine wireless e-mail patents in 2001.

U.S. District Judge James Spencer ruled in favor of NTP in 2003, instructing RIM to halt its sales of BlackBerry devices and services in the United States until NTP's patents run out in 2012.

Spencer stayed the ruling, however, pending appeal. Since then, the case has gone through several appeals and failed settlement attempts.

In the meantime, the U.S. Patent and Trademark Office has spent months re-evaluating several of the disputed patents.

The USPTO has indicated that it intends to reject all of NTP's claims eventually, which would make the case null and void, and RIM officials have remained publicly positive that this will happen.

Industry experts said the process could take several months, though, as NTP has voiced plans to appeal every decision it can. Judge Spencer has said he does not intend to wait for the Patent Office before he issues a final ruling.

On Jan. 23, the Supreme Court refused to hear RIM's appeal to stay the case pending the Patent Office's decisions. On Jan. 25, Judge Spencer set a Feb. 24 hearing date in the Eastern District Court of Virginia to consider a possible injunction that could shutter BlackBerry service.

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