If I include an open source library in my project that is licensed under the MIT license, but contains BSD-licensed code that requires attribution (correctly attributed inside the project), is it my responsibility to attribute it again if I decide to use that library? Normally this is not a problem (I would just credit everyone regardless of the license) but on a mobile platform there is not a lot of real estate or efficient ways to show / bundle these licenses.
BSD does not always require one to credit the author in the gui of their appplication.
As a matter of fact, only the 4-clause license (original "BSD License") requires attribution outside the source code and binary code of the application.
It states as follows:
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. All advertising materials mentioning features or use of this software must display the following acknowledgement: This product includes software developed by the <organization>. 4. Neither the name of the <organization> 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 <COPYRIGHT HOLDER> ''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 <COPYRIGHT HOLDER> 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.
The revised 3-clause licence has removed clause #3.
The later (FreeBSD) 2-clause licence has also removed clause #4.
That means that if the library uses the any BSD licence, you do need to attribute it somewhere in your gui.
In this case, perhaps adding a colophon page to your application might be a solution.