Mini:Visvo
Visvo is an open source search engine similar to Wikia based in Richardson, Texas. Visvo in coordination with Wikia is hosting a fully open index built on the same technologies as Wikia's index including Nutch and Hadoop. The open source python management framework, used by Wikia Search, for running the Nutch clusters and automating fetching and indexing was developed at Visvo. Visvo's search feed is open and freely available for browser and web 2.0 based clients to search:
Visvo's open index will serve results in XML and JSON format. There are a few different url parameters (query, hitsPerSite, lang, hitsPerPage, and type). The query parameter is your url encoded query. The hitsPerSite is the number of duplicates per site. The hitsPerPage parameter is the number of results to return in a single page. The type parameter is xml or json. The default is xml if no type is specified.
Here is an example search for java returning 10 json results:
http://open-index.visvo.com/nutchsearch?query=java&hitsPerSite=2&lang=en&hitsPerPage=10&type=json