According to several sources — including “Macworld” (http://www.macworld.com) and “The Loop” (http://www.loopinsight.com), Apple’s legal department has come to the defense of iOS app developers with a letter to Lodsys regarding its patent dispute with app developers.

In the letter to Lodsys, Bruce Sewell, Apple senior vice president and general counsel said, ““Apple is undisputedly licensed to these patents and the App Makers are protected by that license,” wrote Bruce Sewell, Apple Senior Vice President and General Counsel.”

“Thus the technology that is targeted in your notice letters is technology that Apple is expressly licensed under the Lodsys patents to offer to Apple’s App Makers,” he added. “These licensed products and services enable Apple’s App Makers to communicate with end users through the use of Apple’s own licensed hardware, software, APIs, memory, servers, and interfaces, including Apple’s App Store. Because Apple is licensed under Lodsys’ patents to offer such technology to its App Makers, the App Makers are entitled to use this technology free from any infringement claims by Lodsys.”

Lodsys is suing some iOS developers for using in-app purchasing systems that it claims violates patents it owns. The patent holding firm has been targeting small iOS developers with notices of patent infringement for providing in-app purchase and/or Apple App Store purchase links within their apps.

The company said developers had to obtain a license within 21 days or face the prospect of a lawsuit. Lodsys has been criticized by some for targeting app and website publishers instead of Apple itself.