8. Query Server

The Query server is an external process that communicates with CouchDB by JSONprotocol through stdio interface and processed alldesign functions calls:views, shows, lists and more.

The default query server is written inJavaScript, running via Mozilla SpiderMonkey.You can use other languages by setting a Query server key in the languageproperty of a design document or the Content-Type header of atemporary view. Design documents that do not specify a language propertyare assumed to be of type javascript.

原文: http://docs.couchdb.org/en/stable/query-server/index.html