Under the recently announced Open Patent Non-Assertion Pledge (OPN) Google promises not to sue any person or entity for using their pledged patents in the process of developing, distributing or using any Free or Open Source Software that might contain source code implementing such patents. The pledge does not apply to non open source software, but they are open to discuss “suitable arrangements with interested parties for other software implementations relating to Pledged Patents.”
OPN is open for other companies to adopt. Currently, Cloudera, IBM, and Open Invention Network (OIN) “agree and endorse the OPN Pledge”,
They consider this pledge as legally binding and irrevocable, but maintain the right to terminate it with respect to any recipient that “files a lawsuit or other legal proceeding for patent infringement or who has a direct financial interest in such lawsuit”. The “defensive termination” may be triggered when any company adopting the OPN or distributing product or services including patents covered by the pledge is under attack.
Google has pledged 10 patents relating to MapReduce technology so far, but they intend to add others:
Google intends to expand upon the Pledged Patents over time. We wanted to start first with well known technology and a discrete quantity of patents given the novelty of the OPN Pledge, so we could properly consider public reaction to Our Pledge and incorporate that into the timing and selection of future technologies and related patents for inclusion as Pledged Patents. Stay tuned.
Google provided as a reason for initiating OPN the commitment for “an open Internet—one that protects real innovation and continues to deliver great products and services,” and is meant to be a protection in the face of what they call “patent attacks.”
IBM pledged 500 patents for open source in the past and Red Hat did the same with all their patents.
Update. Hours after Google's announcement to pledge a number of patents for use by the open source community, Microsoft has announced a transparency initiative publishing a list with all their patents across the world, over 46,000 of them. A few of them seem to be repeated in different countries, but the large majority represents unique patents based their name. It's not clear how useful is this move considering the fact that a software manufacturer still needs to license those patents if needed and to go throught hundreds of thousands or millions of patents worldwide to make sure they are not breaking one of them. This may be useful though to help companies protect themselves from patent trolls suggesting they own certain Microsoft patents which they actually don't.