Summary

MarkLogic 5 does not support a dialect that conforms to XQuery 3.0.  

Details

At the time of this writing, Xquery 3.0 is a "Working Draft" (http://www.w3.org/TR/xquery-30/). MarkLogic remains abreast of and contributes to the XQuery standards as we have employees who are members on the XQuery 3.0 Working Group and one who is an editor of the XQuery 3.0 Working Draft. 

You can find a list and description of the XQuery dialects that MarkLogic Server implements in the "XQuery Dialects in MarkLogic Server" section of the MarkLogic Server's XQuery and XSLT Reference Guide available on our developer website at http://developer.marklogic.com/pubs/5.0/books/xquery.pdf.  The "MarkLogic Server Enhanced (XQuery 1.0-ml)" dialect implements some of the functionality that you will find in the XQuery 3.0 Working Draft, such as the try / catch() expression.