[LLVMdev] Licensing requirements

[Chris Lattner]

On Jul 5, 2011, at 7:37 AM, Tor Gunnar Houeland wrote:

> My impression from reading http://llvm.org/docs/DeveloperPolicy.html#clp 
> is that it's intended to be possible to compile programs using llvm and 
> distribute the resulting binaries freely. This does not seem to be the case.
> 
> I'm assuming no portion of LLVM is included in the compiled binaries, 
> only the runtime library components, so that the compiled binaries are 
> not derived from LLVM. Is that true?

This is true if you use clang.  If you use the LLVM libraries to build other compilers, it depends on that compiler.

> 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.

> And finally, could it be possible to change the licensing (again) so 
> that no notices would be required?

Not sure what you mean.

-Chris