After nearly a year of waiting, a federal judge has granted Apple's motion to intervene on behalf of iOS developers in a legal shakedown initiated by patent troll Lodsys. Specifically, Apple will now be allowed to argue that iOS developers—who were sued over alleged patent infringement for using iOS's in-app purchasing APIs—do not infringe because Apple already obtained a license to the patent in question.

Lodsys first made waves when it started sending threatening letters to various iOS developers claiming that using in-app purchasing violated a patent it acquired from Intellectual Ventures titled "Methods and systems for gathering information from units of a commodity across a network." Apple told Lodsys to back off, noting that it already had a license to the patent in question that the company had obtained through prior investment in Intellectual Ventures. Lodsys responded by saying that Apple's license did not extend to third-party developers, and starting suing anyway.

Apple filed a motion to intervene in the lawsuit, which eventually grew to target a number of Android and other developers. Though Lodsys tried to block Apple's motion, Apple insisted it had a material interest in the case. "None of the [current] defendants have the technical information, expertise, and knowledge regarding how Apple's technology works or the negotiation and intent of the License itself to fully articulate and develop Apple's exhaustion defense," Apple noted in its supporting brief.

Apple refers to the legal concept of "patent exhaustion," which generally means that Apple created its in-app purchasing APIs using (among other things) the technology licensed from Intellectual Ventures. Since Apple already paid to use that technology, the company argues that developers incorporating the technology by using Apple-supplied APIs shouldn't be targeted for separate licensing fees.

Apple's motion to intervene was filed last June, and developers entered 2012 still unsure if Apple would be able to assist in their defense. As noted by FOSS Patents, the original judge assigned to the case had since resigned, and the case had to be reassigned. The new judge overseeing the case, Judge Rodney Gilstrap, agreed that Apple should be allowed to present evidence of its patent exhaustion argument on behalf of iOS developers.

Google, for its part, is attempting to have Lodsys's patents ruled invalid by the US Patent & Trademark Office. Apple is not permitted to discuss the possibility that the patents may be invalid, but will be limited to discussing its license of the patents in the suit.

Listing image by Photograph by Luis Argerich