MIThril Hardware Design GPL Interpretation, v 1.0

 Copyright (C) 2001, MIT Media Lab.
                     Building E15, Room 383
                     20 Ames Street, Cambridge, MA 02139 USA

			       Preamble

The purpose of this document is to disambiguate the application of the
Gnu General Public License to licensing hardware design.  It is the
intent of the authors to make clear how the language of the GPL is to
be interpreted in the specific case of hardware design documents that
are licensed under the GPL as construed by the MIThril Hardware Design
GPL Interpretation.

	      MIThril Hardware Design GPL Interpretation
			 Terms and Conditions

0. This interpretation of the GPL applies to any work that contains a
notice placed by the copyright holder saying it may be distributed
under the terms of the Gnu General Public License version two (or
later) as construed by the MIThril Hardware Design GPL Interpretation. 

1. The terms "the program" or "other work" shall be interpreted to
   refer to the hardware design being licensed.

2. The term "source code" shall be interpreted to refer to the files
   and engineering documents that specify the design, hereafter to be
   referred to as the "document package."  The "preferred form" for
   the contents of the document package are toolchain- and
   platform-independent representations.

   a) The document package MUST include well-specified,
      human-readable, platform-independent design documents.  These
      documents should be complete and detailed enough to allow
      another skilled designer to understand the functioning of the
      design, to produce "compiled" representations and to facilitate
      the creation of derived works. (See "Note 1" below.)

      For instance, the document package for a mature, well-elaborated
      electronic device design would include complete schematics and
      PCB layouts represented in PostScript, PDF or some other widely
      accessible graphical form, an ASCII or HTML bill of materials,
      and complete ASCII net and pin lists.  If the design employs
      programmable logic devices (such as FPGAs, PALs or GALs) the
      document package would include the Hardware Description Language
      (HDL) ASCII source code for properly programming these devices.

   b) For the sake of completeness, the document package SHOULD
      include the tool-specific representations used to generate the
      "preferred form" design documents described above, for example
      Eagle, Protel, or xcircuit design files.  However, such
      tool-chain specific design files are not a substitute for
      toolchain- and platform-independent representations. (See the
      "Discussion" section below.)

3. The terms "Binary," "executable," and "object code" shall be
   interpreted to mean:

   a) CAM files, FPGA cores, and other "compiled" representations
      (such as the Gerber and Excellon CAM files used by PCB
      fabrication equipment) sufficient to execute the design but not
      intended for human interpretation or modification.

   b) The physical objects resulting from executing the design
      (printed circuit boards, sub-assemblies, fully functioning
      devices, etc.).

4. The terms "running" or "executing" the program shall be interpreted
   to mean executing the design (fabricating the device) OR using the
   device resulting from the execution of the design.

			      Discussion
      
Human readability, completeness of representation, and
platform-independence are more important for the "preferred form" of
the work than providing support for particular design tools, even free
tools, since the world of hardware design is currently dominated by
closed-source tool chains.

As open-source tool chains mature, it may become feasible to
standardize the "preferred form" of at least some representations
based on these tools.  Until then, the burden will be on the designer
to produce appropriate documentation for cross-tool-chain development.
 
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Note 1: 

"Completeness" here refers to the description, not the design.  A
preliminary design may be well documented with less material than a
fully elaborated design, and a "production" design intended for
turn-key fabrication may require more.  The point is that the
documentation should be adequate for the intended purpose.