Free Software used in Webots

Webots uses three free software libraries: ODE for the dynamics engine, Qt for the graphical user interface, and OGRE for the graphics rendering engine. We are grateful to the Open Source community for all these high quality pieces of software. We also contribute as much as possible to the development of Open Source Software (we contributed to fix many bugs in the open source software we use). Here are the respective licenses for the open source software used in Webots:

ODE License

Open Dynamics Engine
Copyright (c) 2001,2002, Russell L. Smith.
All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

Neither the names of ODE's copyright owner nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Qt Open Source Edition

This software is used under the terms of the Lesser GNU General Public License (LGPL) versions 2.1, and under the terms of the GNU General Public License (GPL) versions 3.
OGRE Open Source License (LGPL)

Ogre’s default license is the GNU Lesser Public License (LGPL), with some exclusions (see below). This basically means that you can get the full source code for nothing, so long as you adhere to a few rules.

Under the LGPL you may use Ogre for any purpose you wish, and modify it if you require, as long as you:

  1. Pass on the (modified) Ogre source code with your software, with original copyrights intact
    1. If you distribute electronically, the source can be a separate download (either from your own site if you modified Ogre, or to this site if you used an unmodified version) – just include a link in your documentation
    2. If you distribute physical media, the Ogre source that you used to build your application should be included on that media
  2. Make it clear where you have customised it.

The above is a precis, please do read the full license agreement.

In addition to the LGPL license text, the following exceptions / clarifications to the LGPL conditions apply to OGRE:

  1. Making modifications to OGRE configuration files, build scripts and configuration headers such as OgreConfig.h in order to create a customised build setup of OGRE with the otherwise unmodified source code, does not constitute a derived work
  2. Building against OGRE headers which have inlined code does not constitute a derived work
  3. Code which subclasses OGRE classes outside of the OGRE libraries does not form a derived work
  4. From 1 March 2009, statically linking the OGRE libraries into a user application does not make the user application a derived work.
  5. Using source code obsfucation on the OGRE source code when distributing it is not permitted.

As per the terms of the LGPL, a “derived work” is one for which you have to distribute source code for, so when the clauses above define something as not a derived work, it means you don’t have to distribute source code for it. However, the original OGRE source code with all modifications must always be made available.