Question: Which software uses GTK+ as programming language?
SPARQL:
SELECT DISTINCT ?uri WHERE {?uri <http://dbpedia.org/property/programmingLanguage> <http://dbpedia.org/resource/GTK+>  . ?uri <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Software>}