I'm looking at the best platform to build a web application that would have a strong natural language search component.

As the rest of the application isn't all that complicated and most web frameworks can handle that part, I'm thinking that having a mature, well supported nlp /nls libraries would be a key point of interest. At this point I'm just collecting information from people who have actually used the libraries.

So, if you were looking to do natural language search, what libraries would you reach for? Why? Can you give pro and con for your choice(s)? I know this isn't a question that has a right or wrong answer... just a quest for more information/background so I can narrow down my research some.

I'm looking at the best platform to build a web application that would have a strong natural language search (question answering) component.

As the rest of the application isn't all that complicated and most web frameworks can handle that part, I'm thinking that having a mature, well supported nlp /nls NLP/NLS libraries would be a key point of interest. At this point I'm just collecting information from people who have actually used the libraries.

So, if you were looking to do natural language search, what libraries would you reach for? Why? Can you give pro and con for your choice(s)? I know this isn't a question that has a right or wrong answer... just Just a quest for more information/background so I can narrow down my research some.