Ms-Pl license: Do I have to disclose the source code of a program using a Ms-Pl licensed library?

Question

Here is what I want to do:

• Modify an MS-PL licensed library so that it suits my needs
• Use the compiled form of said library in my closed source program (linked dynamically)
• Ship the program and the library in binary form
• Ship the source of the modified library with the program and continue licensing it under MS-PL (if legally necessary)

Is this legal?

MS-PL is the Microsoft Public/Permissive License and is used for many Codeplex projects. You can find it here: http://www.microsoft.com/opensource/licenses.mspx

Answer 1

I believe it is legal in many cases

• 2A, Copyright Grant, "reproduce its contribution, prepare derivative works of its contribution, and distribute its contribution or any derivative works that you create.", so you are free to modify it.
• 2B, Patent Grant, the original source might be patented, but MS grant you the right to use already

however, it really depends what license with your other codes

• If you distribute any portion of the software in compiled or object code form, you may only do so under a license that complies with this license.

For example, it is not compatible with GPL. GPL will force the linked ms-pl codes must be GPL, but you have not granted the right to change the license of their codes.