SPARQL is the standard RDF query language. AllegroGraph provides full support for SPARQL 1.1 Query and Update. The documentation includes

SPARQL Reference
A reference for AllegroGraph's SPARQL implementation.
SPARQL Query Engines
There are two query engines named SBQE and MJQE. This document describes them and explains how to specify which one to use.
SPARQL Query Analysis
Sample REST interface requests that provide information on what indices would be best for a query and what are available.
SPIN is a SPARQL representation for rules and constraints. This document describes AllegroGraph's spin implementation.
Describes AllegroGraph's implementation of the W3C SHApes Constraint Language.
Magic Properties
A magic property is a SPARQL predicate that produces bindings using something other than simple sub-graph matching. This document describes AllegroGraph's magic properties and how they integrate SPARQL with freetext indexes, geospatial queries, temporal reasoning, Social Networking Analysis, and direct reification.
Defining Magic Properties Tutorial
AllegroGraph lets you define your own Magic Properties using the Lisp API. The tutorial describes how to do this and provides numerous simple examples.
Lisp S-Expression Syntax
A description of the Lisp S-Expression syntax used by the SPARQL 1.1 query engine.
AGWebView SPARQL Tutorial
A SPARQL tutorial using AllegroGraph's WebView.
SPARQL Lisp Tutorial
A SPARQL tutorial using Lisp.
Release notes
Notes on the status of the SPARQL implementation.