[LLVMdev] Licensing requirements

Tor Gunnar Houeland houeland at pvv.org
Wed Jul 6 01:55:53 PDT 2011

On 07/06/2011 05:13 AM, Chris Lattner wrote:
> On Jul 5, 2011, at 7:37 AM, Tor Gunnar Houeland wrote:
>> The runtime library components state that they are licensed under
>> http://www.opensource.org/licenses/mit-license.php which does not
>> contain a specific clause regarding binary redistribution. This seems to
>> have been interpreted as not placing any restrictions on binary
>> redistribution, i.e. that "all copies" has somehow been interpreted as
>> "copies in source code form". (Different licenses such as Boost, zlib,
>> and bzip2 etc. do not require copyright notices for binary redistributions.)
>> Is it sufficient to include the MIT copyright notices from
>> http://llvm.org/svn/llvm-project/compiler-rt/trunk/LICENSE.TXT /
>> http://llvm.org/svn/llvm-project/libcxx/trunk/LICENSE.TXT for programs
>> compiled with LLVM? (Probably including the respective CREDITS.TXT files
>> as a courtesy, although there doesn't seem to be any actual requirements
>> to indicate that it's for Compiler-RT/libc++)
> There is no need to include any notices in the binaries of an application built with clang, or some with some other application that links to the LLVM runtime libraries that are dual licensed.
Thanks for your response. Is this ability to distribute binaries without 
notices based on your personal assertion that the MIT license used does 
not require them? (I do not use clang but I assumed you were just 
clarifying front-end vs back-end, and that it's not because of a 
guarantee offered to clang users, an automatic inclusion of the notice 
stuffed inside binaries created using clang, or anything like that?)

The license in LICENSE.TXT actually lists the following conditions, 
which do not exclude binaries:

     The above copyright notice and this permission notice shall be 
included in
     all copies or substantial portions of the Software.

(See e.g. http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=610257 , 
http://ideas.opensource.org/ticket/45 , about:license#expat in Firefox 
compared to about:license#optional-notices , or Help->Acknowledgments in 

Is there anything else that would permit distributing the runtime 
libraries without complying with the LICENSE.TXT conditions?

   - Tor Gunnar

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