The most recent version of the exporter and the documentation are located on BlenderWiki
If you want to support me - become a subscriber and get the Personal Edition
For Blender 2.5+ you will need another version: look there
inspired by Yorik's 2d-profile exporter script i went back to Stani's Python library to generate DXF files and adopt it to work in Blender today. It is a first draft - don't await to much! There are only mesh and curves to LINEs support now. GUI and 3DFACE support are planed. I need your feedback.
PLEASE post your questions and bug reports in this thread.
Edit: updated version 1.25beta needs intensive testing before integration in release 2.48
Edit: updated version 1.27beta 2008.10.07
Edit: updated version 1.34 - 2009.06.08
Edit: updated version 1.37 - 2010.06.23