Open-source full-text article recommendation engines

Question

I'm wondering if there are any good .NET recommendation algorithms available in open source projects, whether attached to a search engine or not. By recommendation I mean something that accepts a full-text article and recommends other articles from its index based on keyword similarity.

At the high end there are document classification engines like Autonomy; at the low-end spam filters and blog "related posts" widgets. Possibly advertisement-to-article matching, too. I'd like to incorporate one into a project but can't afford the high end and the low end seems to all be LAMP-based.

[Sorry, one answer asked for clarification: What I'm looking for is ideally a standalone library, but I'm willing to adapt good source code as necessary. The end result is that I need to be able to create a C# service that accepts an arbitrary amount of text and returnsa list of similar previously-indexed articles. Basicallly, the exact thing that StackOverflow itself does as you are submitting a question!]

Thanks! Steve

Answer 1

Question is not very clear (algorithm or library???) but only thing that comes to mind is Lucene.NET, the porting of the popular Lucene library on the .Net framework. HTH.

Answer 2

I think that in StackOverflow they extract all common english words from the text and then compare this words with the remaining words of other posts to get the "Related" posts.