STIR Registration
Introduction
The STIR software is protected by international copyright. However,
we decided to give everyone the opportunity to use and change it, but
under some licensing restrictions.
Unfortunately, due to historical
and commercial reasons, the licensing situation is somewhat complex.
Here is an overview (see below for more details on the
licenses):
- Most of the available software is licensed under the Apache 2.0 license.
- The current software is based on previous work by the
PARAPET project (see also the CREDITs).
Hence, a lot of the files are protected by the
PARAPET license.
- The implementation of the Fourier rebinning algorithm is covered by both the PARAPET license
and the Lesser GNU Public License 2.0.
License details
We do not give a thorough discussion of the licenses.
We only attempt here to give a short and informal overview of our
understanding.
You have to read the licenses to get the full details.
Apache 2.0 license
The Apache 2.0 license is a permissive license,
but with some more conditions than BSD-style licenses. See the link for more details.
Parapet Project Software Distribution Agreement
The PARAPET license states more or less
that you can have the software,
and use it for any purpose at all, under the condition that
"the partners in
the Parapet Project are individually acknowledged in that use"
.
GNU licenses
The Free Software Foundation (http://www.gnu.org) is a non-commercial
organisation that has a long standard in providing Open Source
software. The main intention of the (L)GPL licenses is to make the software
(and source code) available to everyone to use, while protecting the
interests of the developers by putting restrictions on distribution of
software incorporating the software.
The FSF has 2 licenses available, the
GNU General Public License
(GPL) and the
GNU Lesser GPL, see also
the FSF's page on licenses. These
licenses both use the copyleft mechanism to make sure that any
redistributed derivative of the licensed software has to have a
license compatible with the original one (in particular, enforcing
making source code available). The difference between the GPL and the
LGPL is that the LGPL allows commercial (or non-LGPL) programmes to
link with the library (you still have to
distribute the source of the library), while the GPL forces any application using the
software to be GPL'ed as well.
Summary
- If you use this software, you have to give credit to the PARAPET
project and to STIR.
- Unless you use the Fourier rebinning code, you are also bound by the
Apache 2.0 license.
- If you distribute an application that links with the Fourier rebinning implementation
(which you potentially modified), you have to distribute the (modified)
source code of the library part of STIR as
well, protected under the LGPL. See section 6 of the LGPL for full details.
Warranty?
All licenses disclaim all warranty.
Registration
There is no longer any need to register for STIR. Just proceed to the
section for registered users.
Last modified: May 2 2021