Explanation & Hint:
- Can allow software to be used inside closed source software: This is indeed a defining trait of permissive software licenses. These licenses permit the incorporation of open source software into proprietary software without the requirement to disclose the source code of the proprietary additions. Examples include the MIT License and the BSD licenses.
- Are not approved by the FSF: The Free Software Foundation (FSF) does approve many permissive licenses as “free software” licenses because they provide the freedom to use, study, modify, and redistribute the software. However, the FSF prefers copyleft licenses because they ensure that all modified versions of the software remain free as well. While the FSF may not advocate as strongly for permissive licenses as it does for copyleft licenses, it still recognizes many permissive licenses as legitimate free software licenses.
- Don’t have a copyleft provision: This is accurate for permissive licenses. Unlike copyleft licenses (e.g., the GPL), permissive licenses do not require that modifications or distributed works also be open source. This lack of a copyleft provision is a key feature of permissive licenses, allowing for greater flexibility in how the software can be used, including in proprietary projects.
Overall, permissive licenses are recognized by the FSF as being part of the broader category of free software licenses, but they are distinct in not containing copyleft provisions and allowing integration into closed source software. |