I can access WMS and WFS using SOAP and XML. Is there an option to access it using REST and JSON?
I have gone through the specification and couldn't even find the word REST mentioned once.
As @PolyGeo suggested, I am converting my comments into an answer. The answer is split into three parts to broadly reflect the three comments I made.
Roy Fielding's dissertation that described Representational State Transfer (REST) amongst other architectural styles Architectural Styles and the Design of Network-based Software Architectures was published in 2000.
The dissertation tells us:
Since 1994, the REST architectural style has been used to guide the design and development of the architecture for the modern Web. This chapter describes the experience and lessons learned from applying REST while authoring the Internet standards for the Hypertext Transfer Protocol (HTTP) and Uniform Resource Identifiers (URI)...
The name "Representational State Transfer" is intended to evoke an image of how a well-designed Web application behaves: a network of web pages (a virtual state-machine), where the user progresses through the application by selecting links (state transitions), resulting in the next page (representing the next state of the application) being transferred to the user and rendered for their use.
REST is not intended to capture all possible uses of the Web protocol standards. There are applications of HTTP and URI that do not match the application model of a distributed hypermedia system.
Numerous OGC web service interface standards have been published since the REST architectural style was described ~ WMS 1.1.1 (2002), OWS Common 1.0 (2005), WCS 1.0 (2005), WMS 1.3.0 (2006), WFS 2.0.0 (2010), OWS Common 2.0 (2010), WCS 2.0 (2012) etc... The list is not comprehensive, but you can see that the opportunity to define a RESTful way of interfacing with spatial data through OGC services has existed for some time, just not implemented, either because there has been no demand until recently, or because the style doesn't naturally fit.
So it is possible currently to have output delivered to you from an OGC service in some JSON formats (though none of these formats are defined by OGC), for example you can get both WMS (GetFeatureInfo) and WFS to supply you with JSON.
OGC is currently looking to define some JSON based formats for the transfer of Geospatial data, for example OM-JSON for Observation and Measurement data.
OGC is also currently looking at how it might address REST in relation to their web service interface standards, for example the next versions of WFS and OWS common are looking at this aspect.