The Lab is set up in order to experience the SW technlogies by hands. A description of the tools follows.

• The RDF triplifier can be used to build a graph that is stored locally in a triple store. Arcs and nodes can be added to the graph as triples serialized in a RDF/XML document. For example you would like to add some statements about you and the people you know providing your FoaF file stored somewhere in your pc or on a web server over the Internet. A FoaF file is a document that uses specific, standard or otherwise shared, vocabularies to describe people. The use of well defined vocabularies to describe a person's data results in a machine-understandable document that can be read by any software agent once it is reachable over the Internet or intranet. The FoaF Vocabulary is written using the RDF language and can be used to make some statements about a person. Other vocabularies can be used to add other statements that cannot be stated using the FoaF terms only. If you don't have yet a FoaF file you can write one from scratch following the specifications or, more easily, using a simple online editor like FOAF-a-Matic for instance, that let you enter your data in an HTML form and gives you the resulting FoaF file in RDF/XML format. You can check for the validity of your FoaF file using the W3 RDF Validation Service. Once you have your valid FoaF file in RDF/XML format you can upload it in a web server. If you have put your FoaF file in a web server over the Internet you have just to write its URL into the suitable form field otherwise you have to copy and paste it in the form.
• The SPARQL player can be used to traverse the graph in the triples store following the arcs that join its nodes. If you know a little bit of the SPARQL Query Language you can start traversing the graph by writing some query into the form. The SPARQL Query Language is an SQL-like language that can be used to query an RDF repository that stores the triples. The RDF data model permits you to add every kind of statements, or triples you may need to describe people, things or whatever, once you have declared the vocabularies you use. So some people can put in their FoaF file just his/her name using the foaf:name property, others can add people they know using the foaf:knows property of the FoaF Vocabulary, others yet can add their home location by means of its latitude and longitude expressed, for example, in terms of the geo:lat and geo:long properties of the Basic Geo Vocabulary. The RDF data model differs from the relational one for its greater flexibility. The relational data model doesn't let you insert data that doesn't fit into a fixed column in a table whereas a RDF triple can be always added to a graph. The SPARQL query can be written in the form and sent to the triple store in order to find all the triples that match the patterns provided in the query.