What does the X in JAX-RS Stand For? [closed]

Question

In the acronym JAX-RS, what does the X stand for?

I know that RS Stands for Restful Service and J is Java and A for API. What then what about the X?

Answer 1

JAX-RS  = Java API for RESTful Web Services

The X remained as part of the nomenclature. e.g.:

JAXR    = Java API for XML Registries
JAXP    = Java API for XML Processing
JAXB    = Java Architecture for XML Binding
JAX-RPC = Java API for XML-based RPC
JAX-WS  = Java API for XML Web Services  

So, the letter X is for XML.

Answer 2

It was just carried over from JAX-WS and the other javax.ws.rs so it can be said that the x comes from java(x) of the java package.