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DotRas Library Usage Constraints...?

Aug 30, 2010 at 11:13 PM


             Could you please assist me with understanding whether we can use your DotRas software library (that utilizes the LGLP license) within our commercial software application?  I have read the LGLP license many times and there are certain sections that are unclear to me.  Therefore I contacted a solicitor/lawyer to get guidance.  I have paid a substantial amount to my solicitor (to research this license) and the reply is still unclear.  Please see their final reply at the end of this email.

             Our solicitor is basically telling us that the LGLP license is open for interpretation and we should consult FSF foundation to get clear guidance as to whether we can use such a library (I tried contacting FSF by emial but received no reply).  Hence I am hoping you can provide such guidance so we can proceed to utilize the DotRas LGLP library within our software.  I would be exceptionally grateful if you could review the following text and reply stating whether we can use the library under the LGLP license agreement:

             The Problem:

             We have developed a commercial CAD application which enables users to design various complex assemblies in 3D.  The software is designed to be collaborative thus enabling users from around the world to work on projects.  We want to add security to internet communications hence we want to utilize VPN tunneling technologies.  We have identified your library DotRas ( which is freeware and falls under the LGLP license.  Quite simply our software will reference the DLL (using Dynamic Linking) such that it can establish a VPN connection and then closes it when finished.  


            Our Concern: 

            If we use the DotRas (LGLP licensed library) we will have to make public our software application source code (which we currently sell commercially).

             Im reasonably sure that because we are “dynamically” linking (i.e. loading the library at runtime) our commercial software is not bound by the LGLP license.  However, I need clarification (ideally from the author of the DotRas library) on this matter prior to me being permitted to use it.  I would be very grateful for any guidance that you could provide because we can not afford to peruse this matter any further legally via our solicitors.

            BTW - the library is great, easy to use and I love it!

           Best regards


Aug 31, 2010 at 5:09 AM
Edited Aug 31, 2010 at 5:09 AM

The reason I chose the LGPL over the GPL, is the LGPL has provisions in it (from what I understand) to allow commercial software to use the library without needing to make your product open source. As long as you're directly linking to the library and not linking to something else that links to the library, it is not considered a derivitive work and falls outside the scope of the LGPL... basically you're free to use it. Also, as long as you're using the precompiled binaries or compiling the project source code without making changes to the source code, you don't need to worry about anything. The license begins to get picky when you start making changes (derivitive works) and distributing it. See below:

"A program that contains no derivative of any portion of the Library, but is designed to work with the Library by being compiled or linked with it, is called a "work that uses the Library". Such a work, in isolation, is not a derivative work of the Library, and therefore falls outside the scope of this License." - Section 5.

You may also find this piece of particular interest in regards to your work...

"Thus, it is not the intent of this section to claim rights or contest your rights to work written entirely by you; rather, the intent is to exercise the right to control the distribution of derivative or collective works based on the Library." - Section 2, under sub-section D. This is what I was referring to when you start making changes to the code and distributing it.

Hopefully that clears up any questions you had. Again, I'm not a lawyer but that's my basic understanding of the LGPL.

- Jeff

Aug 31, 2010 at 10:53 AM

Hi Jeff

Many thanks for the explanation – this really helped!

Best regards


Aug 31, 2010 at 2:40 PM

Glad I could clear it up for you. Happy coding!