It's not just commercial use. Non-permissive open source licenses are also frequently incompatible with one another [1]. [1] http://www.gnu.org/licenses/licens

It's not just commercial use. Non-permissive open source licenses are also frequently incompatible with one another [1]. [1] http://www.gnu.org/licenses/license-list.html#GPLIncompatibleLicenses http://www.gnu.org/licenses/license-list.html#GPLIncompatibl...