Previous
From:
http://invisible-island.net/ncurses/ncurses.faq.html#who_claims_it
-------------------------------------
How can it be distributed?
The major ncurses developers (exclusive of Pavel Curtis, who put his work in the public domain several years before) early in 1998 assigned their copyright to the Free Software Foundation, which promised to use the following distribution terms for at least five years.
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, distribute with modifications, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
Except as contained in this notice, the name(s) of the above copyright holders shall not be used in advertising or otherwise to promote the sale, use or other dealings in this Software without prior written authorization.
Is it Free Software or Open Source?
Ncurses is free software. It is not `open source'.
That term applies to a mixture of proprietary software and quasi-free software, and is being promoted currently by several people for a variety of reasons: some as a compromise (in the pejorative sense) between free software and proprietary, and others to take credit for brokering the release of some proprietary software under less stringent conditions.
By relabeling free software (and revising the order of causes and events), the supporters of `open software' are doing the development community a disservice.
Is it GPL'd?
Surprisingly, some people cite ncurses as an example of GPL or LGPL. The copyright notice (which is the above-quoted license) appears 577 places in the 5.1 sources, including all of the header files. Presumably therefore, these people have not actually looked at ncurses.
Adding to the confusion are misleading comments such as this:
In particular, if you intend to port a proprietary (non-GPL'd) application using Cygwin, you will need the proprietary-use license for the Cygwin library. This is available for purchase; please contact sales@cygnus.com for more information. All other questions should be sent to the project mailing list cygwin@sources.redhat.com.
By omitting some of the facts, this paragraph states in terms of ncurses, for example, that I cannot work on ncurses on cygwin without buying a license for Cygwin. The same applies to the developers of about half of the contributed software for Cygwin, since not all are GPL'd. There is a better attempt at explaining Cygwin licensing here, but the other page does not use it:
This means that you can port an Open Source(tm) application to cygwin, and distribute that executable as if it didn't include a copy of libcygwin.a/cygwin1.dll linked into it. Note that this does not apply to the cygwin DLL itself. If you distribute a (possibly modified) version of the DLL you must adhere to the terms of the GPL, i.e. you must provide sources for the cygwin DLL.
Probably more people read the FAQ (and are misled) than read the licensing page.
This type of license, by the way, is often referred to as "MIT-style", referring to the MIT X distribution terms. Before assigning copyright to the FSF, substantial portions of ncurses were copyrighted in this style. The main restriction that affects most people is that the copyright notice must be kept on copies - or portions of the copies. That is not done in this online reference, which documents an older version of ncurses. The translation from manpage to html retains the content, but removes the copyright notice, which one may observe is not permitted. Compare with this (copyright notices are retained in the online content, as you can see in the source-view of the page).
For what it's worth, the agreement which we (original ncurses developers) made with the Free Software Foundation reads in part:
The Foundation promises that all distribution of the Package, or of any work "based on the Package", that takes place under the control of the Foundation or its agents or assignees, shall be on terms that explicitly and perpetually permit anyone possessing a copy of the work to which the terms apply, and possessing accurate notice of these terms, to redistribute copies of the work to anyone on the same terms. These terms shall not restrict which members of the public copies may be distributed to. These terms shall not require a member of the public to pay any royalty to the Foundation or to anyone else for any permitted use of the work they apply to, or to communicate with the Foundation or its agents in any way either when redistribution is performed or on any other occasion.
As is well known, that precludes relicensing to the GPL in any version, since it would place restrictions on which programs may link to the libraries. That would deprive a substantial fraction of the current user base of the use of subsequent versions of the software. No such restriction exists in the ncurses license.
