aJson is an Arduino library to enable JSON processing with Arduino. It easily enables you to decode, create, manipulate and encode JSON directly from and to data structures. By this you don’t have to bother with data encoding and decoding – this will aJson handle for you. aJson is a library to receive, understand, create or modify JSON strings directly in the Arduino. aJson provides functions to parse JSON strings to object models. Handle, search and create and modify JSON Object structures.

[interactive-matter] published an interesting tool to implement XML-structured communication using Arduino.

There always have been solutions like XML for structured data. But XML is hard to decode, complicated an takes up a lot of space. And then there is JSON.
JSON is described best on json.org:

It’s like XML, but fat-free. You use it to move data around, store things, or just generally represent your program’s state.
JSON is especially useful to exchange data efficiently with e.g. JavaScript, Java, C++, Processing or anything else

the project is hosted on Github, more on [Interactive-Matters]. As it’s said by [Marcus] at the end of his post:

If you notice any problem just file an issue so that I can deal with it.

Still no issues: I’ll keep an eye on this and try to play around the library myself.

Bravo.