MyBB has historically used the Lesser GNU Public License Version 3 (LGPL3) for the MyBB 1.8 series, and the GNU Public License Version 3 (GPL3) in earlier releases.

Both of these licenses are open source licenses, though both have a fair few limitations. The basic limitations of these licenses are best described by TLDRLegal.

For MyBB 2.0, we decided that we wanted to follow a much more clear and simple licensing model. Several licenses were considered, including the extremely open MIT license. In the end, it was decided that both MyBB 2.0 and all of the associated libraries will be released under the BSD 3 Clause (BSD-3) license, which reads as follows:

Copyright (c) 2015, MyBB Group
All rights reserved.

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

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

2. 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.

3. Neither the name of the copyright holder 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 HOLDER 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.

This license is much simpler than previous licenses, and has the following basic limitations:

• You cannot use the MyBB Group trademark or the names, trademarks or logos of any of the project’s contributors.
• The MyBB Group cannot be held liable for any damages caused by the software.
• The original copyright must be retained.

This change shouldn’t mean much to many of our average users, and will require no changes in many cases. If you do have any concerns about any legal impact this may have upon you or your sites, please do open a thread in our Private Inquiries forum though we do not claim to be legal experts and a legal professional should be consulted if you have any real concerns.

We hope that this license change will make life a lot easier for users of both the MyBB software and our libraries.