Lori MacVittie, Senior Technical Marketing Manager at F5 Networks (www.f5.com), says:

While everyone was focused on cloud, JSON has slowly but surely been taking over the application development world.

It looks like the debate between XML and JSON may be coming to a close with JSON poised to take the title of preferred format for web applications.

If you don’t consider these statistics to be impressive, consider that ProgrammableWeb indicated that its “own statistics on ProgrammableWeb show a significant increase in the number of JSON APIs over 2009/2010. During 2009 there were only 191 JSON APIs registered. So far in 2010 [August] there are already 223!”

Today there are 1262 JSON APIs registered, which means a growth rate of 565% in the past eight months, nearly catching up to XML which currently lists 2162 APIs. At this rate, JSON will likely overtake XML as the preferred format by the end of 2011.

This is significant to both infrastructure vendors and cloud computing providers alike, because it indicates a preference for a programmatic model that must be accounted for when developing services, particularly those in the PaaS (Platform as a Service) domain.

PaaS has yet to grab developers mindshare and it may be that support for JSON will be one of the ways in which that mindshare is attracted. Consider the results of the “State of Web Development 2010” survey from Web Directions in which developers were asked about their cloud computing usage; only 22% responded in the affirmative to utilizing cloud computing. But of those 22% that do leverage cloud computing, the providers they use are telling:

PaaS represents a mere 7.35% of developers use of cloud computing, with storage (Amazon S3) and IaaS (Infrastructure as a Service) garnering 26.89% of responses. Google App Engine is the dominant PaaS platform at the moment, most likely owing to the fact that it is primarily focused on JavaScript, UI, and other utility-style services as opposed to Azure’s middle-ware and definitely more enterprise-class focused services. SaaS, too, is failing to recognize the demand from developers and the growing ascendancy of JSON.

If JSON continues its steady rise into ascendancy, PaaS and SaaS providers alike should be ready to support JSON-style integration as its growth pattern indicates it is not going away, but is instead picking up steam. Providers able to support JSON for PaaS and SaaS will have a competitive advantage over those that do not, especially as they vie for the hearts and minds of developers which are, after all, their core constituency.

What the steady rise of JSON should trigger for providers and vendors alike is a need to support JSON as the means by which services are integrated, invoked, and data exchanged.

Application delivery, service-providers and Infrastructure 2.0 focused solutions need to provide APIs that are JSON compatible and which are capable of handling the format to provide core infrastructure services such as firewalling and data scrubbing duties. The increasing use of JSON-based APIs to integrate with external, third-party services continues to grow and the demand for enterprise-class service to support JSON as well will continue to rise.

There are drawbacks, and this steady movement toward JSON has in some cases a profound impact on the infrastructure and architectural choices made by IT organizations, especially in terms of providing for consistency of services across what is likely a very mixed-format environment. Identity and access management and security services may not be prepared to handle JSON APIs nor provide the same services as it has for XML, which through long established usage and efforts comes with its own set of standards.

Including social networking “streams” in applications and web-sites is now as common as including images, but changes to APIs may make basic security chores difficult. Consider that Twitter – very quietly – has moved to supporting JSON only for its Streaming API. Organizations that were, as well they should, scrubbing such streams to prevent both embarrassing as well as malicious code from being integrated unknowingly into their sites, may have suddenly found that infrastructure providing such services no longer worked:

API providers and developers are making their choice quite clear when it comes to choosing between XML and JSON. A nearly unanimous choice seems to be JSON. Several API providers, including Twitter, have either stopped supporting the XML format or are even introducing newer versions of their API with only JSON support. In our ProgrammableWeb API directory, JSON seems to be the winner.

Similarly, caching and acceleration services may be confused by a change from XML to JSON; from a format that was well-understood and for which solutions were enabled with parsing capabilities to one that is not.


The fight between JSON and XML is one we continue to see in a general sense. See, it isn’t necessarily the API that matters, in the end, but the data format (the semantics) used to exchange that data which matters.

XML is considered unstructured, though in practice it’s far more structured than JSON in the sense that there are meta-data standards for XML that constrain security, identity, and even application formats. JSON, however, although having been included natively in ECMA v5 (JSON data interchange format gets ECMA standards blessing) has very few standards aside from those imposed by frameworks and toolkits such as JQuery. This will make it challenging for infrastructure vendors to support services targeting application data – data scrubbing, web application firewall, IDS, IPS, caching, advanced routing – to continue to effectively deliver such applications without recognizing JSON as an option.

The API has become little more than a set of URIs and nearly all infrastructure directly related to application delivery is more than capable of handling them. It is the data, however, that presents a challenge and which makes the developers’ choice of formats so important in the big picture. It isn’t just the application and integration that is impacted, it’s the entire infrastructure and architecture that must adapt to support the data format.

The World Doesn’t Care About APIs – but it does care about the data, about the model. Right now, it appears that model is more than likely going to be presented in a JSON-encoded format.