The State of RDF in Ruby [closed]

Question

I'm wondering about the current support there is in Ruby for semantic web technologies. Is there good RDF options? It seems that the last surveys done were circa 2007 ( http://paul-classic.stadig.name/2007/10/26/the-state-of-rdf-support-in-ruby-2007/ ). Is Redland's RDF wrappers the best way to go for RDF support - all the other projects mentioned in that aging article seem to be unsupported or dropped. Is Ruby perhaps a bad choice if one which to pursue projects pertaining to the semantic web?

Answer 1

I just wrote up a new survey article on Ruby and RDF. Some of my conclusions are:

• There's a huge amount of activity surrounding RDF.rb, with over a score of database adapters, serialization/deserialization plugins, and interfaces to other libraries. Most of the recent object mappers have been built on top of RDF.rb, too.
• The popular Redland RDF library has Ruby bindings, and it's actively maintained.
• ActiveRDF was the premiere object mapper for RDF, but it no longer appears to be actively maintained.
• The only recent, active object mapper at the moment appears to be Spira.
• None of the object mappers are taking advantage of ActiveModel yet. This would be really slick, because it would provide much deeper integration between RDF and Rails.

There are also some interesting follow-up comments from the authors of RDF.rb and Spira. Ben Lavender, in particular, has thought a lot about how to sanely map RDF onto Ruby objects.

Answer 2

AllegroGraph (RDF DB) has a Ruby Client - https://github.com/phifty/agraph

Answer 3

There is a Ruby Sesame library: http://github.com/tillsc/ruby-sesame

Sesame is one of the two most popular RDF frameworks for Java. We (Ontotext) develop a triple storage + built-in inference engine called OWLIM. We provide a free version called SwiftOWLIM.

Some of our users use it with Ruby through the above Ruby Sesame library.

Answer 4

Check out RDF.rb http://rdf.rubyforge.org/

Answer 5

I'm the author of Redland but I don't use Ruby myself. The ruby bindings probably still work (they passed the unit tests at the last release) but probably need some love for any newer ruby language changes.

Pure Ruby users I think have tried Active RDF which is more recent than the other things you suggest but focused on Rails.

Otherwise I suggest asking on the Semantic Web Interest Group IRC channel - #swig on irc.freenode.net

Edit: There's also Reddy http://github.com/tommorris/reddy/tree/master and other ruby rdf code on github if you look around.

Answer 6

Personally I went for RDF.rb as their web site had OK documentation, and it was easy to get started with using the blog tutorials.

ActiveRDF seems like a larger project - but their wiki is down (actually the main page links to a copy of the wiki on archive.com) - and all the example talk about SPARQL queries.

Here's a simple triple lookup example, apologies for silly syntax as this was my first Ruby script:

require 'rubygems'
require 'rdf'
require 'rdf/raptor'

scufl2 = RDF::Vocabulary.new("http://ns.taverna.org.uk/2010/scufl2/ontology/")
dc = RDF::Vocabulary.new("http://purl.org/dc/elements/1.1/")

graph = RDF::Graph.load("../resources/workflows/example.ttl")
graph.query([nil, scufl2.workflow, nil]) do |bundle,p,workflow|
  graph.query([workflow, scufl2.name, nil]) do |wf,p,workflow_name|
    # Should just be one
    print workflow_name
  end
end

Unfortunately, like many Ruby and Python dependencies, this also needed some binaries to be able to read Turtle or RDF/XML. "aptitude install raptor-utils" took care of that, though.