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. Moreover, we will ask you to
fill in a registration form.
Unfortunately, due to historical
and commercial reasons, the licensing situation is somewhat complex.
Here is an overview (see below for more details on the
- Most of the available software is a library, which you can use
to build your own stand-alone application.
The library is available under the
GNU Lesser General Public License.
- We distribute some applications as well, including the actual
reconstruction algorithms. These applications use the above library,
but are available under the
GNU General Public 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
We do not give a thorough discussion of the licenses.
We only attempt here to give a short and informal overview of our
You have to read the licenses to get the full details.
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 give credit and
distribute the source), while the GPL forces any application using the
software to be GPL'ed as well. This is done by requiring that any GPL
program can only use other software components whose license is
compatible with the GPL. However, note that a commercial application
can still run a GPL'ed program, as long as it is clear it is used as a
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".
- If you use this software, you have to give credit to the PARAPET
project and to STIR.
- If you distribute an application that links with the library part of
STIR (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.
- If you distribute a (modified version) of a STIR application, you
have to do this under the GPL.
All licenses disclaim all warranty.
If after all this, you still think STIR is for you (I wouldn't know why not), then you have to read the
GNU Lesser GPL and the
Then click the appropriate button below.
Last modified: Mon Jun 22 20:18:31 GMT 2009