3kbo

Last week-end I installed ActiveRDF on my Mac OS X Powerbook, together with the Sparql, RDFLite and Redland adapters. Ideally I am working towards setting up an environment that allows me to build RESTful Semantic Web Applications that support reasoning over RDF data and implement a SPARQL query end point. Support for OpenID authentication, integrated with FOAF, is also at the top of the list.

On the Powerbook I could also install the ActiverRDF adapters for Sesame and Jena to give me the functionality that I am after but that only works in my development environment. Sesame and Jena are Java based. When it comes to deploying an application onto the web my options are currently more limited. 3kbo is deployed into hosted environment which supports PHP, Python, Ruby and Ruby On Rails and PERL, but no Java. (There is C/C++, limited to my local user account.)

Currently there are two PHP SPARQL implementations, ARC and RAP. RAP also provides a reasoning engine InfModel, with support for owl:sameAs and owl:inverseOf.

So at this stage the architecture that is emerging is an ActiveRDF RESTful Ruby On Rails application that uses RAP as the triple store, SPARQL query engine and reasoning engine. To integrate Rails with PHP I am planning to implement a RESTful PHP interface that acts as a facade to RAP.

OpenID is based on the fundamental concept that a URI identifies a resource. Given the large number of web sites that require a user to logon it makes sense to use a unique URI to identify each person. That way each person can managed his or her own user name and password on just one server. This is premise of the OpenID security system.

To use OpenID a user can either register with an OpenID Provider such as myOpenId or Videntity or implement their own OpenID server by using one of the available OpenID Code Libraries .

For 3kbo I’ve used the Verselogin Wordpress OpenId Plugin which enables the use of both OpenIDs and normal login with a username and password.

The Verselogin Wordpress OpenId Plugin install (using vesion wpopenid.86.tgz ) worked fine apart from needing to customize the login dialog box.

To login to an OpenID-enabled website such as this one, just type your OpenID URI. The website will then redirect you to your OpenID Provider to login using whatever credentials it requires. Once authenticated, your OpenID provider will send you back to the OpenID-enabled website with the necessary credentials to log you in.

The presentation by Scott Kveton at the Ignite Seattle conference 2007-02-13 is an excellent overview of OpenID.