Groovy Server Pages (GSP) 
This project contains the sources for GSP, the server-side view rendering technology used in Grails.
Documentation
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Latest - http://gsp.grails.org
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Latest - http://gsp.grails.org/latest/api
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Snapshot Guide - http://gsp.grails.org/snapshot
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Snapshot API - http://gsp.grails.org/snapshot