Open Source Licenses
Executive Summary
All PSAS works (e.g., documents, documentation, source code, firmware, CAD/EDA files) should be copyrighted (to identify them as ours) and licensed under the the Free Software Foundation's General Public License v2.0 (in order to release them in an beneficially open, time-honored way).
Introduction
We've had a few people ask about copyrights and other licenses for PSAS documentation, code, and hardware. We did a bit of research, and decided that you can waste an unbelievable amount of time and effort trying to get your licenses right. There are all sorts of documentation licenses. There are all sorts of software licenses. And there are even open hardware licenses. Most of these are not used very much (meaning they've never really been tested), and most are obtuse enough to make understanding them a real challenge.
Not only are licenses terribly confusing and arcane, it's not our objective to worry about these kinds of things. But according to ourselves, we're an open group. From Introduction:
All projects we do are "open source", from our CAD drawings to schematic diagrams to our software. We pride ourselves in sharing what we learn with the world of amateur rocket enthusiasts, and with our ability to collaborate with other groups.
So here's our take on licensing our works.
Software and Firmware Licenses
For software we should obviously use the GPL. Since we're an open educational group, we'd like our software to be available to be used by everyone, so an "always available source code" license is better than the "do what you want" like the Berkeley license. Here's the license text we've been using, which belongs at the top of every source file:
/*
* LICENSE:
*
* <name of file> - <short description of what the code in the file does>
* Copyright (c) <year> Portland State Aerospace Society
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
* USA.
*
* Portland State Aerospace Society (PSAS) is a student branch chapter
* of the Institute of Electrical and Electronics Engineers Aerospace
* and Electronics Systems Society. You can reach PSAS at
* info@psas.pdx.edu. See also http://psas.pdx.edu/
*/
Hardware Licenses
For hardware, there is no good answer. The various open hardware licenses are overly specialized or overly legal. Richard Stallman points out that since hardware is never really gratis (free-of-cost), open hardware licenses are not as important. But the design for hardware is sometimes software (VHDL) and you can apparently argue that CAD/EDA designs are in some respect the source code of the design. But apparently you can't really copyright hardware, so this might be all moot. But we can through the GPL at this problem anyway, and it will get across the intended idea: if you distribute our hardware, the end user should get the EDA files.
Here's the statement we should be making on all CAD/EDA files:
Copyright (C) <year> <name of author> (<address or contact of author>)
Redistribution allowed under the terms of the GNU General Public License version 2 or later.
For your personal work for PSAS:
Copyright (C) 2004 Josephine Q. Public (Josephine@psas.pdx.edu)
Redistribution allowed under the terms of the GNU General Public License version 2 or later.
Or if you just wish to attribute it to the group:
=Copyright (C) 2004 Portland State Aerospace Society (
Redistribution allowed under the terms of the GNU General Public License version 2 or later.
Documentation Licenses
Here's a discussion of documentation licenses, which sparked the entire license debate:
But what about for documentation? What licenses are best to achieve our goals? Several possibilities seem to be common: 1. No copyright. Same as public domain. Same as expired copyright. Possibly non-copyright restrictions may still apply. Also note that works without copyright notice may still have undiminished copyright protection, this is a function of the applicable jurisdiction. Commonly, lack of notice does not mean lack of copyright. 2. "All rights reserved", No copying allowed except "fair use" and "first sale". 3. GPL, the most popular opensource license. Designed specifically for software but may be applied to other source material. Quoting the GPL, "The source code for a work means the preferred form of the work for making modifications to it." 4. FDL or "Free Documentation License" Another GNU license designed for book length material such as manuals or text books. There are other free documentation licenses in use, but they are obscure because of their infrequency. None of these choices are very good. The FDL http://www.gnu.org/copyleft/fdl.html would seem the natural choice, but their are several problems. See: http://people.debian.org/%7Esrivasta/Position_Statement.xhtml The problems with the FDL are mostly that it disallows any digital rights management(DRM), even for private copies, and that it always requires source form distribution. The FDL also allows for invariant sections, but this is not a requirement of the FDL. Disallowing any DRM is presumably intended to prevent FDL material being used in proprietary ebooks, etc., however the language appears to include private copies which might for example exist on encrypted drives. Probably the DRM issue is not too severe for our purposes, and may even be a non-issue generally. It may also be remedied in a later version of the FDL. It's worth noting that the spectacular wikipedia uses the FDL. http://en.wikipedia.org/wiki/Wikipedia%3ACopyrights The requirement of source form distribution may also be a problem (or not) for both the FDL and the GPL. I interpret the source- requirement clause to mean that if the document is a Microsoft Word document, then the distribution must enable access to the actual Word .doc (GPL) or that the distribution must include the actual .doc (FDL). Either of these requirements might be problematic for us for example if we are posting PDFs derived from .doc's, but do not want to distribute the .doc's. Fortunately, it seems reasonable to assume that the license applies to the published form. So in the previous example, the .pdf file would be covered under the opensource license but the .doc file would not. (Even though the .doc presumably contains a reference to language claiming that it falls under an opensource license, interesting eh?) Personally i'm inclined to just GPL stuff and take my chances. That's what i've done with the document i edited today. Here's why. Taking no copyright is being too nice. First, we may want some attribution. Also the viral properties of opensource copyrights can be construed as positive community building. Similarly the full copyright is both too restrictive and disturbingly ambiguous. The FDL is too long. Having a license invocation longer than the document is almost as scary as "All rights reserved. Also, the FDL is too geared to authorship. I care more for free content than rigorous attribution (phenomenology over prejudice, nothing against references though). The FDL is unproven. Many voices have questioned some of its provisions, and though it is probably usable in its current form, its whole effect will probably become clear only with the passage of time. Making up our own copyright agreement is too much work, besides almost nobody would understand it. That last point applies to almost any opensource license except the GPL. Even though the GPL may only be awkwardly applied outside the realm of computer software. Using it seems to make sense for us. Eventually some sort of net-wide standard for broader opensource material will emerge and we can then embrace that. The transition should be painless because we can expect that the spirit of both licenses will be consistent. There are a few more technical details. We probably should add a copyright link at the bottom of our TWiki pages similar to the Wikipedia pages. Whether the copyright is retained by the author or assigned to PSAS is mostly irrelevant. I see two issues. If copyright is retained by the author, then the version published by PSAS is forever covered by an opensource license. The author could however re-publish or derive any work under any other applicable copyright. Second, suit may only be brought by the copyright holder. Currently the style of copyright notice we're using is:
Copyright (C) <year> <name of author> (<address or contact of author>)Redistribution allowed under the terms of the GNU General Public License version 2 or later.If you look around, you will see that many notices are longer. I argue that this version is sufficient. The reasoning is this. If a reader intends to copy part of the covered material they may do so either under the prevailing copyright law, that is fair use and first sale, or under the terms granted. Longer notices, if they are in any way superior, can only serve to reduce ambiguity in the terms granted, but in the form presented ambiguity is already negligible.
So here's our official documentation blurb:
Copyright (C) <year> <name of author> (<address or contact of author>)
Redistribution allowed under the terms of the GNU General Public License version 2 or later.
For your personal work for PSAS:
Copyright (C) 2004 Josephine Q. Public (Josephine@psas.pdx.edu)
Redistribution allowed under the terms of the GNU General Public License version 2 or later.
Or if you just wish to attribute it to the group:
=Copyright (C) 2004 Portland State Aerospace Society (
Redistribution allowed under the terms of the GNU General Public License version 2 or later.