Google has been slowly developing tools and technologies to support its unique requirements. I'd like to use this post to catalog information about them.
BigTable is google's answer to the database. Wikipedia has a good article on it here.
MapReduce is google's answer to workflow. The article is here.
Sawzall is google's high level distributed language. The paper is here.
GFS is google's file system. The article is here.
6 hours ago