Hello there. I'm considering using an open source rendering engine as part of a game engine I wish to develop. The engine is the Geometric Tools Engine and it uses the Boost License. The engine can be found here: http://geometrictools.com. I will need to modify the rendering engine over time and make improvements. Therefore my rendering engine will be a derivative work. I am unclear about a few things when it comes to licensing. GPL requires any program using GPL code to include the copyright notice at the top of all source files and also with any binaries when the derived program is distributed. However, the Boost License is a lot less restrictive. A copy of the license does not have to be included with the executable of the derived software but must be included in the source file when the code is distributed. It also states that any code distributed alongside code covered by the license is not subject to the license's requirements. This brings me to my first question:
Assuming I want to fork the rendering engine and keep it private (which the license permits), can I also add my own copyright notice under a different license to source files in the modified engine that I add? So if I create a new class and I modify an existing class from the original code to link to it, can that new class still have my copyright under a different license? I assume the code I add to the original class cannot be licensed differently.
My second question is related to leaked code:
Let's say I set up a company and develop software derived from software covered by the Boost License and an employee leaks the derived code. Seeing as the derived code is also covered by the Boost License, can anyone obtaining the leaked code legally use it for their own purposes? Even though it may be covered by an open source license, it was not the intention of the author for the code to be distributed.
Thanks for any answers or suggestions.