Looks cool. From looking at their public github projects it seems like they use Ruby + Rack a lot. I would love to know the implementation details. Can't wait for my beta invite.
Business-wise, I do wonder how many people will be interested in hosted RDF data storage. I am comparing them with companies like cloudant.com for CouchDB and mongohq.com for MongoDB: more wider used data stores.
Their paper (stub placeholder) "Storing RDF Data using Cassandra" may indicate that they are using Cassandra for distributed DF storage. Very cool. https://github.com/datagraph/papers
Their FAQ (bottom of the page) mentions Ruby, Rails, custom Lisp distributed SPARQL query engine, Redis, message queues, etc.
“We’ll share more details in upcoming blog posts, but the website is built with Ruby and Ruby on Rails, relying heavily on the RDF.rb framework. Our back-end infrastructure is based on core technologies such as ZeroMQ, AMQP, and Redis. Our proprietary distributed SPARQL query engine, called SPOCQ, is built in Lisp. Our distributed RDF storage system is built in Ruby and C, relying on Raptor and Rasqal in particular. Our stack as a whole is hosted on Amazon Web Services.”
It's interesting that all the docs and APIs are open and they advertise that, but say nothing about the platform. It's great for the client to be open and for users to own their data, which presumably is RDF and very portable, but risky to invest in building anything that's dependent on a closed platform. I suppose it comes down to what service level agreements are provided for the service.
Business-wise, I do wonder how many people will be interested in hosted RDF data storage. I am comparing them with companies like cloudant.com for CouchDB and mongohq.com for MongoDB: more wider used data stores.