Does google search allow querying via API similar to yahoo boss?

Yahoo's BOSS API allows one to query the Yahoo search database and return values back to the calling program for extraction and usage. Does Google offer a similar tool or API for developers?

I understand that Yahoo BOSS is set to beg开发者_运维技巧in charging for queries in excess of 10k per day and I have a shipping plugin which pulls data on demand from this engine, so I'm looking to allow the end user to choose their search provider in order that I can spread the risk.

Yes it does. JSON/Atom Custom Search API

Yes - the google custom search API. There was once a SOAP API, but it is deprecated now.

See this announcement