Few works are released directly to the public domain. It is my understanding that the public domain doesn't even exist in all legal jurisdictions.
Most people license out the software under specific requirements and prohibitions. BSD requires attribution. GPL variants require adherence to copyleft when distributing derivative works. A little under half of all github repos don't even have a license, which means that though the source is published, no one has any license under which to copy it or derive new works from it.
So far as I have seen, whether aggregating and munging these works into abstract LLM weights constitutes fair use is still legally unclear. If not deemed fair use, it is almost certainly a massive violation of copyright.
Most people license out the software under specific requirements and prohibitions. BSD requires attribution. GPL variants require adherence to copyleft when distributing derivative works. A little under half of all github repos don't even have a license, which means that though the source is published, no one has any license under which to copy it or derive new works from it.
So far as I have seen, whether aggregating and munging these works into abstract LLM weights constitutes fair use is still legally unclear. If not deemed fair use, it is almost certainly a massive violation of copyright.