There are similar question, but not regarding C# libraries I can use in my source code.
Thank you all for your help.
I've already saw lucene, but I need something more easy to search for similar strings and without the overhead of the indexing part.
The answer I marked has got two very easy algorithms, and one uses LINQ too, so it's perfect.
Levenshtein distance implementation:
I have a .NET 1.1 project in which I use the latter. It's simplistic, but works perfectly for what I need. From what I remember it needed a bit of tweaking, but nothing that wasn't obvious.