Editing Interoperability (section)

==Interoperability and open standards==
Interoperability implies exchanges between a range of products, or similar products from several different vendors, or even between past and future revisions of the same product. Interoperability may be developed ''[[wikt:ex post facto|post-facto]]'', as a special measure between two products, while excluding the rest, by using [[open standard]]s.{{elucidate|reason=How does using an open standard exclude others?|date=April 2022}} When a vendor is forced to adapt its system to a dominant system that is not based on open standards, it is [[Computer compatibility|compatibility]], not interoperability.{{cn|date=April 2022}}

===Open standards===
{{Main|Open standard}}
Open standards rely on a broadly consultative and inclusive group including representatives from vendors, academics and others holding a stake in the development that discusses and debate the technical and economic merits, demerits and feasibility of a proposed common protocol. After the doubts and reservations of all members are addressed, the resulting common document is endorsed as a ''common standard''. This document may be subsequently released to the public, and henceforth becomes an ''open standard''. It is usually published and is available freely or at a nominal cost to any and all comers, with ''no further encumbrances''. Various vendors and individuals (even those who were not part of the original group) can use the standards document to make products that implement the common protocol defined in the standard and are thus ''interoperable by design'', with no specific liability or advantage for customers for choosing one product over another on the basis of standardized features. The vendors' products compete on the quality of their implementation, user interface, ease of use, performance, price, and a host of other factors, while keeping the customer's data intact and transferable even if he chooses to switch to another competing product for business reasons.

===''Post facto'' interoperability===
{{Original research|section|date=August 2016}}
''Post facto'' interoperability may be the result of the absolute market dominance of a particular product in contravention of any applicable standards, or if any effective standards were not present at the time of that product's introduction. The vendor behind that product can then choose to ''ignore'' any forthcoming standards and not co-operate in any standardization process at all, using its near-monopoly to insist that its product sets the ''de facto'' standard by its very market dominance. This is not a problem if the product's implementation is open ''and'' minimally encumbered, but it may well be both closed and heavily encumbered (e.g. by patent claims). Because of the [[network effect]], achieving interoperability with such a product is both critical for any other vendor if it wishes to remain relevant in the market, and difficult to accomplish because of lack of cooperation on equal terms with the original vendor, who may well see the new vendor as a potential competitor and threat. The newer implementations often rely on [[clean-room reverse engineering]] in the absence of technical data to achieve interoperability. The original vendors may provide such technical data to others, often in the name of ''encouraging competition'', but such data is invariably encumbered, and may be of limited use. Availability of such data is ''not'' equivalent to an open standard, because:
# The data is provided by the original vendor on a discretionary basis, and the vendor has every interest in blocking the effective implementation of competing solutions, and may subtly alter or change its product, often in newer revisions, so that competitors' implementations are almost, but not quite completely interoperable, leading customers to consider them unreliable or of lower quality. These changes may not be passed on to other vendors at all, or passed on after a strategic delay, maintaining the market dominance of the original vendor.
# The data itself may be encumbered, e.g. by patents or pricing, leading to a dependence of all competing solutions on the original vendor, and possibly leading a revenue stream from the competitors' customers back to the original vendor. This revenue stream is the result of the original product's market dominance and not a result of any innate superiority.
# Even when the original vendor is genuinely interested in promoting a healthy competition (so that he may also benefit from the resulting innovative market), post-facto interoperability may often be undesirable as many defects or quirks can be directly traced back to the original implementation's technical limitations. Although in an open process, anyone may identify and correct such limitations, and the resulting cleaner specification may be used by all vendors, this is more difficult post-facto, as customers already have valuable information and processes encoded in the faulty but dominant product, and other vendors are forced to replicate those faults and quirks for the sake of preserving interoperability even if they could design better solutions. Alternatively, it can be argued that even open processes are subject to the weight of past implementations and imperfect past designs and that the power of the dominant vendor to unilaterally correct or improve the system and impose the changes to all users facilitates innovation.
# Lack of an open standard can also become problematic for the customers, as in the case of the original vendor's inability to fix a certain problem that is an artifact of technical limitations in the original product. The customer wants that fault fixed, but the vendor has to maintain that faulty state, even across newer revisions of the same product, because that behavior is a de facto standard and many more customers would have to pay the price of any interoperability issues caused by fixing the original problem and introducing new behavior.