Hubble.Tools.TextParse.dll is a library build with .net 2.0 that can convert file to text.
This library is used to index documents using hubbledotnet.
Currently, it support all of the Microsoft office document file types, html file types, text file types and pdf file types.
The source code attached contains a demo can show you how to use it.
If you want to convert pdf to text at 64 bit OS, you have to install Adobe PDF iFilter 9 for 64-bit platforms