Introduction
All eggs and associated code MUST include some form of licence. Below is a brief description of various licences and how to include them. This list is not meant to be complete; it is merely a description of some of the common licences in use and their meanings.
Egg metafile tagging
Licences consisting of initials should be entirely capitalised.
Example: "BSD"
If a licence has a version relevant to its application (eg GPL, LGPL, etc), the tag should contain the licence name, followed by a hyphen, followed by the version.
Examples: "GPL-2", "LGPL-2.1", "Artistic-2".
If a licence consists of multiple words, capitalise the first letter of each word.
Example: "Public Domain"
If multiple licences apply, separate them by forward slashes.
Example: "Public Domain/Free Use"
Common Licences
Public Domain
Public domain licences disavow any form of copyright on the code. There must be a notice of a form similar to the one below included in the relevant files and documentation.
This code is written by YOUR-NAME and placed in the Public Domain. All warranties are disclaimed.
Note: If any form of copyright is retained to the code, it is NOT in the public domain. See Free Use, below.
Free Use
Free Use licences are permissive licences granting complete free usage of the code for any purpose. They differ from Public Domain primarily by the retention of copyright by the owner(s). An example of a Free Use licence would be the SLIB licence, contained below:
Copyright (C) YEAR by YOUR-NAME Permission to copy this software, to modify it, to redistribute it, to distribute modified version, and to use it for any purpose is granted, subject to the following restrictions and understandings. 1. Any copy made of this software must include this copyright notice in full. 2. I have made no warranty or representation that the operation of this software will be error-free, and I am under no obligation to provide any services, by way of maintenance, update, or otherwise. 3. In conjunction with products arising from the use of this material, there shall be no use of my name in any advertising, promotional, or sales literature without prior written consent in each case.
GNU General Public Licence/Lesser GPL
See http://www.gnu.org/licenses/gpl.html for details. Note that these licences must include a version tag in the metafile.
BSD
This is a permissive licence, often referred to as the Modified BSD License. The relevant files should include something similar to the following lines, or contain a reference to a file containing them:
Copyright (C) YEAR, YOUR NAME All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. Neither the name of the author nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.