Legalo is a novel Open Knowledge Extraction approach that performs unsupervised, open domain, and abstractive knowledge extraction from text for producing directly usable machine readable information. The method is based on the hypothesis that hyperlinks (either created by humans or knowledge extraction tools) provide a pragmatic trace of semantic relations between two entities, and that such semantic relations, their subjects and objects, can be revealed by processing their linguistic traces (i.e. the sentences that embed the hyperlinks) and formalised as Semantic Web triples and ontology axioms. Given an English sentence as input, Legalo produces a set of RDF triples representing relevant factual relations expressed in the sentence, the predicates of which are formally defined in terms of OWL axioms. Legalo is available as a REST service returning RDF as output.