Topic Maps, OWL and RDF

It's been quite a while since my last post. This has mostly been due to spending a large amount of time playing with some Topic Map (the Ontopia Omnigator) and OWL (Protege) software. Both of these are excellent applications and I was especially impressed by the ability of OWL to form advanced object relationships.

However, at the end of all this research, I think that neither Topic Maps nor OWL are suitable for my purposes; yes, both can perform complex classifications and describe advanced relationships between classes but, for my purposes of creating a heterogeneous database, I only require simple classifications and relationships. Therefore using either of these technologies would probably be like taking the proverbial hammer to a nut. For me, a stronger argument against using these technologies is that, at this moment in time, neither is freely available for C# - the language that I'd like to work with.

So my requirements are a technology that can describe simple classifications and relationships and that is freely available in C#. The one application that seems to match these requirements is Joshua Tauberer's SemWeb - an RDF library for C#. The RDF and RDFS support provided by this package can perform categorisation and describe the relationships between objects to a level suitable for my requirements. An added bonus is that this library is still under active development - version 1.0 was only released on the 10th June 2007 (unlike the other C# RDF library Drive - the web page of which had actually expired the last time I looked).

This doesn't mean to say that SemWeb is perfect - like most things I've encountered on this journey, using SemWeb is not as straightforward as it could be. The main reason for this is that SemWeb has been developed on Mono, as opposed to Microsoft's Visual Studio that I want to use. As a result of this the supplied Visual Studio solutions are incomplete (I needed to refer to the makefiles to create the required projects) and the package currently doesn't support SQL Server, the Express version of which I'd been using for some other areas of this project (such as user administration). I've therefore now switched databases to use MySQL and am now struggling to add and retrieve some RDF data from this. I'll give more details of this struggle in the next post.