Microsoft Open Specification Promise

The Microsoft Open Specification Promise (or OSP) is a promise by Microsoft, published in September 2006, to not assert its patents, in certain conditions, against implementations of a certain list of specifications. The OSP is not a licence, but rather a covenant not to sue. It promises protection but does not grant any rights. The OSP is limited to implementations to the extent that they conform to those specifications. This allows for conformance to be partial. So if an implementation follows the specification for some aspects, and deviates in other aspects, then the Covenant Not to Sue applies only to the implementation's aspects which follow the specification. Relations with free software / open source projects The protections granted by the OSP are independent to the licence of implementations. There is disagreement as to whether the conditions of the OSP can be fulfilled by free software / open source projects, and whether they thus gain any protection from the OSP.