[pydry]

GPL also wouldnt be needed without software licensing.

No reason Linux couldnt exist. All software would effectively be FOSS by default.

[GuB-42]

Free but not open source.

GPL is here to make sure the source code doesn't stay secret, and it is an essential part of the Linux development process, the driver model in particular. In fact, I don't see how a community driven, widely supported, monolithic kernel could be made without a copyleft license.

Linux without GPL wouldn't be Linux, and out of the free OSes (BSD, GNU/HURD, Haiku, Minix, ...), Linux is the most successful.

[pydry]

If every employee of your company were able to take and release your source code anyway the GPL couldnt really make things more open.