Conceptual Tagging of articles

Question

I have a set of articles and i want to extract the concept from each of the article . The concept may be independent ,or either linked together to form a new concept .

For this ,recently I came across various paid API , eg,HP's IDOL on DEMAND ( http://www.autonomy.com/technology/idol-functions/conceptual-search ) , Data harmony( http://www.dataharmony.com/services-view/mai-components/ ) , ALCHEMY API ( http://www.alchemyapi.com/products/features/concept-tagging/ ) ,etc . But I have a very huge set of documents and cant afford using the priced API .Is there any free tool which can do this ? Also I'am aware of DBPedia data-sets , which are used for linking concepts together. But I haven't figured out how to use them . Any help on that would be useful .

Also, I had used Stanbol NLP tools long back .I wanted to know whether this could be done thru that , or for that matter by any other tool .

Answer 1

I realise that this doesn't answer your question about Stanbol, but HP's IDOL OnDemand is open to the public and is currently completely free as-in-beer. As you've identified it as a potential solution, now would be the time to try it out!

Disclaimer: I work for HP and am involved with IDOL OnDemand.