Synopsys and Magma officials were not readily available for comment Thursday night, but according to the press release, Synopsys and Magma have agreed to release all claims in both California and Delaware and to cross-license the patents at issue in these jurisdictions as well as any related applications.

The companies both agreed not to initiate future patent litigation against each other for two years, provided certain terms are met. Magma also agreed to make a payment to Synopsys of $12.5 million toward the settlement of the dispute. The release also states that the settlement includes other terms that are confidential.

The settlement seemingly favors Magma, as Synopsys was originally seeking an injunction against Magma’s first-generation place-and-route system and hundreds of millions of dollars in damages.

The lawsuit had been dragging on since the fall of 2004 when Magma sent Synopsys a patent-assertion letter claiming Synopsys was violating certain patents. Synopsys then turned around and sued Magma for patent infringement in the US District Court for Northern California claiming that a former Synopsys employee who moved to Magma allegedly invented the technology portrayed in the patents in question while still employed at Synopsys.

The legal battle then escalated with a Magma countersuit claiming ownership of the patents and infringement by Synopsys. Later Magma filed an antitrust suit against Synopsys in Delaware Court. Synopsys also added more patent-infringement claims against Magma in Delaware Court. Over the course of the last four years, ownership of the claims became increasingly hazier—some of the patent claims were thrown out, proven invalid or jointly owned by Synopsys and IBM (which had a cross-licensing agreement with Magma) and Synopsys even made some of the patents in dispute public domain.

The settlement announcement doesn’t come as a surprise, as last month, the companies issued a release that Magma had dropped its antitrust suit. Shortly afterward, on an industry panel, executives from the two companies acted in a cordial manner for the first time in a very long time, and Magma CEO Rajeev Madhavan indicated the suit was winding down. Magma's stock is certain to jump in the wake of news that the litigation between the companies is now over.