Linux – What Linux/Unix software to use to convert html or pdf to doc

dos2unix is a commandline utility that will do this, or :%s/^M//g will if you use Ctrl-v Ctrl-m to input the ^M, or you can :set ff=unix and Vim will do it for you.

There is documentation on the fileformat setting, and the Vim wiki has a comprehensive page on line ending conversions.

Alternately, if you move files back and forth a lot, you might not want to convert them, but rather to do :set ff=dos, so Vim will know it's a DOS file and use DOS conventions for line endings.

The Aspose.Words component can do this reliably (I'm not affiliated or anything).

iTextSharp does not have the required feature set to load and process MS Word file formats.