1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
|
THIS IS THE OPEN SOURCE VERSION OF Qt, RELEASED UNDER THE GPL
LICENSE. PLEASE READ THIS FILE TO FIND OUT WHAT THAT MEANS TO YOU.
INTRODUCTION
============
Qt is licensed under two licenses: the GNU General Public License
(GPL) and a commercial license. You are currently using the Open
Source (GPL) version of Qt. This file explains the principle of dual
licensing, and which obligations using the GPL version of Qt implies.
Please note that it is necessary to choose either the Open Source or
Commercial license at the outset of development. Trolltech's
commercial license terms do not allow you to start developing
proprietary software using the Open Source edition.
ABOUT DUAL LICENSING
====================
Dual Licensing is based on the principle of Quid Pro Quo - something
for something. If you, your company or your organization derive
commercial benefit from Trolltech's products and do not wish to
release your complete source code, you are required to purchase the
appropriate number of commercial licenses.
Alternatively, if you are willing to follow the terms of the GPL
(General Public License), Trolltech software is available to you under
Open Source licenses which allows you to develop, modify and
distribute your software freely. If you wish to use an open source
version of Trolltech's products, you must contribute all your source
code to the open source community, according to the terms of the
applicable open source license.
By offering both open source and commercial licenses, Trolltech
ensures the availability of resources for ongoing development and
improvement of Qt. By purchasing commercial licenses, you are no
longer obligated to publish your source code.
COMMERCIAL AND OPEN SOURCE LICENSES
===================================
Trolltech's Commercial licenses allow customers to develop, use and
distribute their applications under standard commercial terms.
Trolltech's Open Source versions are available under the terms of the
GPL - General Public License. The main obligation for software
development under the GPL is that anyone using your Qt-based software
must have access to the complete source code, and must be able to
modify and redistribute that software to anyone free of charge.
QUESTIONS?
==========
You can find additional information about dual licensing at the
following URLs:
Qt Open Source Edition License FAQ:
http://www.trolltech.com/developer/faqs/license_gpl.html
Qt Commercial Licensing Page:
http://www.trolltech.com/products/qt/licensing.html
Qt Open Source Licensing Page:
http://www.trolltech.com/products/qt/opensource.html
Please contact sales@trolltech.com with any additional questions about
our licensing.
|