Having to extend or develop a web application in PHP with support for Semantic Web technologies, one wonders what are currently the main
frameworks which allow to easily manage structured data in RDF. For PHP, the main framework currently available are:

• ARC2: easy to use, it provides an RDF storage with support for the SPARQL query language, various RDF parsers for numerous formats (RDF/XML, Turtle, RSS, microformats, eRDF, RDFa, etc), serializers supporting numerous formats (N-Triples, RDF/JSON, RDF/XML, Turtle), a templating system and many other stuff. ARC2 is easily extendible developing dedicated plugins.
  
  
• RAP: it provides an RDF storage with support for the SPARQL and RDQL query languages, an inference engine supporting RDF-Schema reasoning and some OWL entailments, an integrated parsers end serializer supporting numerous format (RDF/XML, N3, N-TRIPLE, TriX, etc.), an integrated system to draw RDF graph and a GUI to manage the RDF back-end

What is the best Semantic Web framework for PHP language? It depends from your needs. Anyway, at the moment, it seems that the development of ARC2 is more active than RAP. ARC2 seems also more stable than RAP.

Marcin Wichary and Ernest Delgado have released a very interesting presentation, developed using HTML5 and CSS3, to show “the coming bleeding edge features for modern desktop and mobile browsers”. The presentation is a good starting point to understand the new features introduced in the new standard. The presentation was originally meant to run in Google Chrome but it can be seen in any recent browser with HTML5+CSS3 support (some experimental features might or might not be run in other browsers).