• Username (14/14) May 31 2017 Hello, I've tried to find some information about the license file
• bachmeier (3/18) May 31 2017 This may answer your question:

Username <usernameatdlangforum gmail.com> writes:

Hello, I've tried to find some information about the license file 
for DMD in windows builds(I'm not sure if it's used for other 
platforms). I'm new to D, literally just downloaded the compiler, 
but as far as I understand the licensing of DMD looks like this: 
runtime, phobos and compiler frontend is Boost licensed. And 
compiler backend is also boost licensed but this still does not 
apply to stable build(DMD 2.074.0),as the source files of backend 
provided with that build still contain the old custom license. 
But license.txt file bundled with windows build(probably others 
too) in stable, beta and nightly version states that: runtime and 
phobos is boost licensed, compiler frontend is under GPL license, 
and also contains the custom license text for compiler backend. 
License.txt file is located in dlang/installer repo ( 
https://github.com/dlang/installer/blob/master/create_dmd_release/extras/
ll/dmd2/license.txt ). Is license.txt file just outdated or is it that binary
builds are licensed differently(I'm not really licensing expert, could this be
caused by the bundled libcurl.dll or the windbg tools?)? I'm sorry if this was
answered already but I couldn't find any info about this specific file.

bachmeier <no spam.net> writes:

On Wednesday, 31 May 2017 at 19:51:49 UTC, Username wrote:
 Hello, I've tried to find some information about the license 
 file for DMD in windows builds(I'm not sure if it's used for 
 other platforms). I'm new to D, literally just downloaded the 
 compiler, but as far as I understand the licensing of DMD looks 
 like this: runtime, phobos and compiler frontend is Boost 
 licensed. And compiler backend is also boost licensed but this 
 still does not apply to stable build(DMD 2.074.0),as the source 
 files of backend provided with that build still contain the old 
 custom license. But license.txt file bundled with windows 
 build(probably others too) in stable, beta and nightly version 
 states that: runtime and phobos is boost licensed, compiler 
 frontend is under GPL license, and also contains the custom 
 license text for compiler backend. License.txt file is located 
 in dlang/installer repo ( 
 https://github.com/dlang/installer/blob/master/create_dmd_release/extras/
ll/dmd2/license.txt ). Is license.txt file just outdated or is it that binary
builds are licensed differently(I'm not really licensing expert, could this be
caused by the bundled libcurl.dll or the windbg tools?)? I'm sorry if this was
answered already but I couldn't find any info about this specific file.

This may answer your question:
http://forum.dlang.org/post/och98k$1puh$1 digitalmars.com