Simple Solr Search (S3) is an example web app for searching Apache Solr index using JSON REST interface. It is developed using Mojolicious::Lite.
Apache Solr is popular "blazing fast open source enterprise search platform from the Apache Lucene project. Its major features include powerful full-text search, hit highlighting, faceted search, dynamic clustering, database integration, ..."
The steps to get started with Solr is available here: http://lucene.apache.org/solr/tutorial.html