As the title states, if I take one code project that is under a zlib license, and incorporate it into a GPL3, Apache2 or MIT-licensed codebase, do I have to remove the license from the code project prior to incorporation?
If so, do I also have to change the license of the original code project, in order for the licensing to not conflict with the larger GPL3/Apache2/MIT codebase (since they now share the same code)? Or can I effectively 'grant' use of the code (if I'm the sole owner) under those licenses, without changing the license of the original code?
I realise I am in essense asking 3 different questions here due to the differing conditions of the 3 licenses, but I appreciate any general advice given.
zLib is a more permissive license than the others, and is stated to be compatible with the GPL3.