Screaming Penguin - Source Does Matter

RDF is the Resource Description Framework (Format) specification that is currently still being developed for the distribution and exchange of metadata on the web. Metadata is data describing data. A great example and a major use for RDF are headlines files such as screamRDF.txt (now deprecated - use site.xml) which supplies the current ToTSP headlines to others who wish to use them.

RDF is closely associated with the Rich Site Summary (RSS) specification developed by Netscape to provide the popular "my Netscape" channel functionality. Honestly, there is a lot of confusion about the difference between RDF and RSS as evidenced by how different people refer to them interchangeably (the syntax is different, yet many people name files .rdf and use the rss syntax, or vice versa.) I cannot yet clear up that confusion. My take on it is that RDF is the W3C standard that is being ironed out and RSS is the Netscape semi-proprietary in-the-meantime format (my take could be wrong, I can not find a definitive answer, if any of you know please let me know so I can revise this and credit you.)

Either way both of these formats accomplish the same goal of creating a way to effectively share metadata and use APIs or sandard functions to retrieve it. Prior to this XML based methodology each exchange of information was truly proprietary for each different source. This meant that special code had to be present for each separate data exchange. XML via RDF allows for the seamless explicitly defined exchange of data. (For more XML info see XML.com.)

In order to setup RDF for your site you need to build the RDF file with your content and then let people know where it is. Again, check the ToTSP RDF file for format info. Basically you need to declare XML in the intro and the version number, then declare the RDF format and namespace you will use (the ns is like a dictionary for definitions and formats, this is a universal language so things have to be clearly defined somewhere for reference), then use the CHANNEL declaration for your site with LINK included, then use the IMAGE tag with LINK included for an image if neccessary (my netscape) and finally declare and ITEM tag with TITLE and LINK for each item. Then close the RDF. For exact syntax info please see the W3C RDF page.

Of course this is the ultra over simplified version of the howto, but with this information and the files and sites linked as templates it should be fairly self evident how to provide and or use RDF content. IF you need or have more info or have any questions feel free to ask, and note that if you are interested in the PHP function I have written to pull headlines out of the ToTSP database and put them into RDF format, just let me know.   RDF Resources