for open sourcing you have to be careful about licenses. As long as you are not "distributing" it is absolutely fine to mix GPLv2, Apache License and proprieta

for open sourcing you have to be careful about licenses. As long as you are not "distributing" it is absolutely fine to mix GPLv2, Apache License and proprietary code you got from some vendor all together. But as soon as you distribute this, it becomes messy. And then come all the question on technical integrations, ego ("ugly code!!"), ...