Amid what appears to be interminable rounds of patent feuding, Microsoft, Apple and Google each produced statements or letters on where they stand regarding patents.

Microsoft issued a statement today saying it "will always adhere to the promises it has made to standards organizations to make its standard essential patents available on fair, reasonable and nondiscriminatory terms."

Microsoft said that means it would not seek an injunction against any firm on the basis of those "essential patents," and that the company's approach to such patents is to license them to other firms without requiring cross-licensing ("except for any patents they have that are essential to the same industry standard").

"Our approach is shared by Apple, Cisco and many others in the industry," Microsoft VP and Deputy General Counsel Dave Heiner wrote in a blog post.

Heiner also outlines what "standards essential patents" are: That as technology evolves, new standards are developed (for instance, those technologies used in cellphones or computers) that often involve patented inventions.

Heiner says:

Firms benefit from having their ideas included in new standards, and in exchange for this, firms usually make a promise: that if they have any patents they have that are "essential" to implementing a standard, they will make these patents available to all. In particular, these firms typically promise that they will make these "standard essential patents" available to any firm that wishes to implement the standard on reasonable and nondiscriminatory terms.

Microsoft's policy, though, doesn't prevent the company from suing to get compensation for the use of its essential patent or from taking action against firms that Microsoft believes infringe on its non-industry-standard patentsa Bloomberg article points out.

The Wall Street Journal reports, meanwhile, that Apple had sent a letter to the European Telecommunications Standards Institute to set basic rules governing how companies license their essential patents.

And Google has sent a letter to another regulating body -- the IEEE -- "intended to assure you and any potential licensees that, following Google's acquisition of MMI {Motorola Mobility), Google will honor MMI's existing commitments to license the acquired MMI Essential Patent Claims on RAND terms." (The term RAND is used interchangeably with FRAND. They are acronyms for "reasonable and non-discriminatory" and "fair, reasonable, and non-discriminatory.")

Google's letter is posted on the Foss Patents blog written by intellectual-property consultant Florian Mueller. Mueller, who has been commissioned by Microsoft to conduct a study on the worldwide use of FRAND-committed patents, also includes his analyses of the various companies' patent statements and letters on his blog.

The statements and letters don't appear to change anything, though, in the ongoing patent disputes between the various tech companies.