Question

makes source code available for use, modification, and redistribution as long as licensing terms are met
free and open - source software
proprietary software
copyrighted material
intellectual property

Explanation:

Free and open - source software (FOSS) has the key characteristic of making the source code available for use, modification, and redistribution when licensing terms are met. Proprietary software has source code that is owned by the developer and is not usually available for free modification and redistribution. Copyrighted material and intellectual property are more general terms that can apply to many types of creations (not just software) and do not specifically imply the availability of source code for the actions mentioned.

Answer:

Free and open - source software