Here’s my presentation from SMX Advanced 2012 on structured data use, tools, and how it fits into the SEO ecosystem. I also included a bit of background on how to get started with semantic technology:
A good general list of updated semantic web development tools can be found at http://www.w3.org/2001/sw/wiki/Tools - good place to find RDF browsers.
URIBurner is a utility that uses URLs as data sources, runs it through their middleware and then gives you output in a variety of data forms that conform to various standards (CSV, Turtle, RDF/XML, JSON). For example, here’s the output for this blog post:
One of the newest RDF database options is Stardog: It’s commercial grade, and I’m not sure of the fee structures yet but this is designed for midscale use (re: speed) rather than NASA-level use (re: size). Given the people behind it, this might be end up being the ‘web scale’ RDF database that provides the hooks most web publishers are used to working with.
4Store is an RDF platform operating under the GNU license
Mulgara is an open source RDF database written in Java.
Sesame is probably the most popular consumer level framework for working with RDF data. It supports connection to remote databases via API, a full SPARQL query set, and compatibility with most RDF file formats (RDF/XML ,Turtle, n-Triples, etc).
Hopefully this will help you get started with rolling your own structured data.