Microsoft Reciprocal License: include source even for unmodified binary?

Question

The Microsoft Reciprocal License (here taken from the WIX toolset I use) has the following sentence:

For any file you distribute that contains code from the software (in source code or binary format), you must provide recipients the source code to that file along with a copy of this license

Does that mean I have to provide the source code even if I only use the unmodified (original) DLL in binary format? Note that this unmodified DLL contains code from the software, although it was not compiled by me.

What does provide mean? Shall I provide 11 MB of source code as part of my application (install the source on hard disk) or can I provide it as an extra download as well?

Answer 1

Does that mean I have to provide the source code even if I only use the unmodified (original) DLL in binary format?

Not if you just link to the DLL from your software. Read the license again:

For any file you distribute that contains code from the software (in source code or binary format), you must provide recipients the source code to that file along with a copy of this license

(the software being the DLL, or its original source)

Provide means to supply the source code to the person to whom you're distributing the software (the "user").

Answer 2

The .Net Foundation has clarified that installers built using Wix do not count as derivative works: http://wixtoolset.org/about/license/

Sometimes the reciprocal license is incorrectly interpreted to also apply to bundles, packages, and custom actions built using the WiX toolset. The Outercurve Foundation has previously provided this statement below to clarify which now the .NET Foundation reaffirms:

The WiX toolset (WiX) is licensed under the Microsoft Reciprocal License (MS-RL). The MS-RL governs the distribution of the software licensed under it, as well as derivative works, and incorporates the definition of a derivative work provided in U.S. copyright law. OuterCurve Foundation (and the .NET Foundation) does not view the installer packages generated by WiX as falling within the definition of a derivative work, merely because they are produced using WiX. Thus, the installer packages generated by WiX will normally fall outside the scope of the MS-RL, and any of your source code, binaries, libraries, routines or other software components that are incorporated in installer packages generated by WiX can be governed by other licensing terms.