Type: Vector and 3D
    Extension: DXF
      Version: 
  Compression: None
  Color Depth:
   Maintainer: Autodesk
Specification:

The AutoCAD DXF (Drawing eXchange Format) and AutoCAD DXB (Drawing eXhange
Binary) formats are the native vector file formats of Autodesk's AutoCAD
CAD application.

DXF is probably one of the most widely supported vector formats in the
world today. DXF is rich in features, including: support for 3D objects,
curves, text, associative dimensioning, and is an easy format to parse.
The DXB format is a binary representation of a DXF file and they are
usually smaller and faster to load than the equivalent DXF file.

The latest "official" DXF revision is Release 12. However, there is an
even newer version of DXF containing several changes and additions to the
format.  Apparently the specification of the latest version of the DXF
format is not yet (if it will ever be) freely available. Users are
required to pay $4000US for a license to AutoCAD in to obtain the specs
for this newest release of DXF file format.

The official specification for DXF R12 may be found in the AutoCAD Manual
Release 12:

  AutoCAD Customization Manual, Release 12, Autodesk Inc., 1992, pp. 241-81.

The specification for DXF R12 has also been released in electonic form and
is available in several of the Internet file format archives, such as:

  ftp://avalon.vislab.navy.mil/pub/format_specs/
  http://www.mediatel.lu/mmedia/render/h_dxf12.html

The spec for the most current version, DXF R13, is available at:

  ftp://ftp.synapse.net/private/c/cadsyst/misc/

And an excerpt of the DXF R10 specification may be found at:

  http://www.mediatel.lu/mmedia/render/h_dxf10.html

Many books detail the DXF format, including:

  The AutoCAD Database Book, F.H. Jones and L. Martin, Ventana Press,
    ISBN 0-940087-04-9. Order: 919.490.0062 voice.

  AutoCAD, The Complete Reference, 2nd Ed., Johnson, N., McGraw-Hill,
    New York, NY, 1991.

Additonal information may be obtained directly from Autodesk:

  Autodesk Inc.
  Autodesk Developer Marketing
  2320 Marinship Way
  Sausalito, CA 94965
  Voice: 415.491.8719
  FTP:   ftp://ftp.autodesk.com/
  WWW:   http://www.autodesk.com/