The earliest notable use of DOSP we found is Aladdin GhostScript (TODO: WHEN).
Aladdin's practice was to publish new versions of the software under proprietary
license. It also published versions of its software under GPL if they were
older than about a year.\footnote{CITE}
The earliest notable use of DOSP we found is Aladdin GhostScript, which
was a relicensing (by its original author) around 1998 of the originally
GPL-licensed GhostScript project under the ``Aladdin Free Public License".
Aladdin's practice was to publish all new versions of the software under
this license, which did not permit commercial redistribution. Aladdin also
published versions of its software under GPL once they were older than about
a year, initially as ``GNU Ghostscript" and later as ``GPL
Ghostscript".\footnote{CITE}
GhostScript's author, L. Peter Deutsch, described this practice as providing
commercial exclusivity that would help fund continued development of the
project.\footnote{CITE} This is a commonly cited motivation for adopting DOSP.
% Sort of described in https://web.archive.org/web/20070816214332/http://pages.cs.wisc.edu/~ghost/doc/AFPL/6.01/New-user.htm#Commercial_use which mentions
% the availability of paid proprietary licenses, but this doesn't
% explicitly say that the revenue is going to be used to promote continued
% development.
Interestingly, GhostScript's makers eventually dropped the delay in favor of
dual-licensing.\footnote{CITE and add date} With this approach, they
dual-licensing.\footnote{This change was made in 2006.
% See \otsurl{https://web.archive.org/web/20161003082642/http://ghostscript.com/News.html}.
% TODO But this long URL makes LaTeX very unhappy!
}
With this approach, they
simultaneously release GhostScript under both a proprietary license and GPL.
They continue to use this model today, though they have replaced GPL with
They continue to use this model today, though they have since replaced GPL with
AGPL.\footnote{See \otsurl{https://ghostscript.com/licensing/index.html}.} They determined
that their market of commercial, embedded developers were paying to avoid the
A/GPL, and that the time-delay did not significantly change these companies'
incentives to pay for licenses.\footnote{CITE to Rosen's book?}
that their market of commercial, embedded developers were paying to
avoid the GPL and AGPL, and that the time-delay did not significantly
change these companies' incentives to pay for licenses.\footnote{CITE to Rosen's book?}
% Rosen also says that sendmail may have had a dual license in the same
% era or even before Ghostscript. I found references to sendmail having
...
...
@@ -202,8 +214,9 @@ have had somewhat different understandings.
Today, all of Qt is released simultaneously under LGPL/GPL and proprietary
dual licenses.\footnote{The Qt Group states that there is currently one
exception where it doesn't have the right to grant a proprietary license
for a specific module:
\quote{A few modules in Qt, however, use code from 3rd party open source projects such as the Qt WebEngine is using the Chromiu[m] project licensed under LGPLv2.1. So when using these modules, you will need to fulfill the corresponding license obligations, in case of Chromium the LGPLv2.1.}. See \otsurl{https://www.qt.io/download-open-source}.}
for a specific module, the Qt WebEngine, which is only available under
LGPL v2.1.
See \otsurl{https://www.qt.io/download-open-source}.}
GhostScript and Qt are the two earliest projects we found making
documented use of DOSP. They use them in different ways, but both relate
