There are many flavors of XML and JSON out there now. I think for many developers JSON started to "look good" when the number of standards that started stacking

There are many flavors of XML and JSON out there now. I think for many developers JSON started to "look good" when the number of standards that started stacking up against XML (and XML-ish/SGML-ish/HTML-ish based formats) started to make people go insane. In the healthcare world we typically had to deal with a never ending set of "format standards" that kept integrating themselves together. I guess originally that may have been the beauty of XML... we started with XML RPC, moving on to SOAP 1.0, SOAP 1.1 introduced new ways to send headers. At some point however it just went crazy.. I think kinda when the enterprise-level people got their hands on things, they started porting all of their non-standard wack-job features into XML. WS-Addressing - ok seems simple, but now your SOAP stack has to support async processing. WS-Trust - OK Let's add a simple feature that lets you put "some tokens" in the request and response for security, auditing, non-repudiation - good ideas sure. WS-Eventing - Let's add enterprise queuing to XML and soap and require stacks to support that, let the users of the stack figure out a way to connect that to the queues. Anyway the list goes on, and you can read about it here: https://en.wikipedia.org/wiki/List_of_web_service_specifications https://en.wikipedia.org/wiki/List_of_web_service_specificat... Suffice it to say, but XML died because the developer now had to learn all of these, how they worked because one tiny industry body starts to adopt 1% of each, requiring implementors to learn 99% of all. It basically just made JSON attractive, a reset if you will. XML won't go away. HTML will continue forever (it crosses a developer-designer "human line" that makes it kinda permanent) Developers adapt to future technologies a lot faster than designers and other's dabbling in HTML. Now all this being said, you can see the list of standards piling up against JSON. There's really no critical mass ready replacement though, so JSON will be safe for quite a while longer. JSON will only be replaced in various "areas" like YAML for config, binary JSON-compatible representations for wire and/or storage. I'm not biased against XML for data transfer, but if someone asked me to create a SOAP 1.1 service with WS-Trust, SAML tokens, etc... I'd also argue for a more industry accepted REST service with OAuth tokens, simply because it would be like introducing the Hummer all over again in age where Tesla's are everywhere. - everyone would hate us.