search technologies

• elasticsearch

elasticsearch aims to solve all these problems and more. It is an Open Source (Apache 2), Distributed, RESTful, Search Engine built on top of Apache Lucene.
So, we build a web site or an application and want to add search to it, and then it hits us: getting search working is hard. We want our search solution to be fast, we want a painless setup and a completely free search schema, we want to be able to index data simply using JSON over HTTP, we want our search server to be always available, we want to be able to start with one machine and scale to hundreds, we want real-time search, we want simple multi-tenancy, and we want a solution that is built for the cloud.
http://www.elasticsearch.org/

• JSON

JSON (JavaScript Object Notation) is a lightweight data-interchange format.
It is easy for humans to read and write. It is easy for machines to parse and generate.
It is based on a subset of the JavaScript Programming Language, Standard ECMA-262 3rd Edition - December 1999.
JSON is a text format that is completely language independent but uses conventions that are familiar to programmers of the C-family of languages, including C, C++, C#, Java, JavaScript, Perl, Python, and many others.
These properties make JSON an ideal data-interchange language.
http://www.json.org/