WordPressExportConverter is a project mainly written in C#, it's free.
Transforms WordPress export files to ease transfer between WordPress accounts.
WordPressExportConverter
Originally by David Boike http://www.make-awesome.com/
Processes a WordPress export file, transforming it to ease transferring content between WordPress accounts.
Currently, the only transformation is to change image references so that posts do not contain multi-megapixel images once they are imported into a self-hosted WordPress installation.