I need to understand in simple terms what I can and cannot do with opensource software. For this I'm kindly asking you to explain in simple terms and in short what are my right and obligations for opensource software distributed under GPL and MIT licenses.
More specifically, I need to know the following:
Assume that I have used in my application some parts from an opensource app distributed under the GNU GPL or MIT license.
Can I sell or distribute the compiled application without distributing the source code ?
If the application contains both proprietary code and GPL or MIT code and I'm forced by the licenses to distribute the source, do I have to include in the source distribution the proprietary code also ? Or just publish the modifications I made to the GPL part of the code ?