An application I'm writing is using code/libraries that are licensed under free software licenses; specifically I have code that is licensed under the Apache License V2, GNU GPL V2, and the CPOL V1.02. From what I understand, if the customer request it, I would have to provide them with the source code under the free software licenses, but I don't want to provide the source code for my entire application.
My question is, if I take the three pieces of source code covered under the free software licenses and place them in individual libraries (DLLs) could I then apply a custom (proprietary) license to the rest of my application? This way if someone request the source code under one of the three free software licenses, I can provide the source code just for that library without having to release the source code for the rest of my application.
Would this be appropriate and inline with the license requirements of the free software licenses? Keep in mind that I'm not marketing my software as a free software/open source, but would like to use these libraries and be in compliance with their licenses.
Thanks in advance for any help and/or clarification you can provide. I've read over the licenses several times (as well as articles on them) and I;m still a little confused over the requirements as it applies to using it in closed commercial software.