The CforCUDA_SDK_license.txt file in the SDK says that:
Developer shall have the right to modify and create derivative works with the Source Code. Developer shall own any derivative works (“Derivatives”) it creates to the Source Code, provided that Developer uses the Materials in accordance with the terms and conditions of this Agreement.
but the stock header at the top of each source file says:
NVIDIA Corporation and its licensors retain all intellectual property and proprietary rights in and to this software and related documentation and any modifications thereto.
I’m not a lawyer, but these sound contradictory, with the latter implying that NVIDIA owns all derivative works. Or am I interpreting this incorrectly?