Reading .DXF files

Cadlib from WoutWare have I been using for a couple of projects with good results.

I have work a couple of years at developing my own DXf-Viewer in java (you could drop your own DXF file or an URL on the viewer) for 2D drawings.
The published information from AutoCAD is a good base but doesn't explain how it works.
Becoming member of the Open Design Alliance, will give you the possibility to convert several CAD formats to DXF. It may be a good idea if you are developing a commercial product.
There is a german book (http://www.crlf.de/Verlag/DXF-intern/DXF-intern.html) about DXF which really explain this format. It's expensive, but could save days of search.
The colors in the DXF Format are indexed, you must have a converter from ACI to RGB. Be careful with values 0 and 1 which having a special meaning.

Regards.

Update in case someone is still looking...
It's the same library, just including both links.

https://github.com/haplokuon/netDxf
https://www.nuget.org/packages/netDXF/