The GPL, or copyleft, does not require you to release your changes. 10:31 in the video: "And they can also offer it to the rest of the public, if they wish." I

The GPL, or copyleft, does not require you to release your changes. 10:31 in the video: "And they can also offer it to the rest of the public, if they wish." It doesn't matter whether you're just using a program, or also hacking away at it, being a developer/programmer means you're also using it, i.e. means you're also a user of the program. So compared to users, developers don't lose anything, except for the fact that they are not allowed to turn a program into an instrument of power over other users. I don't know why you say ideology > people above. If anything, copyleft really favours the people as the majority of people are not programmers. Even for programmers, copyleft has incentive for them to contribute since it's a guarantee that their investment into the program will not be 'wasted', i.e. used in proprietary software (if the programmer believes in the morality of free software that is, obviously it can go both ways). > "I'm also not sure why you'd need the GPL license to ensure the users' freedom." If it's licensed under MIT, you can simply continue development under a proprietary license at anytime (and typically you would stop distributing the source, only distributing the binary). Eventually, the unmaintained MIT licensed version will likely become useless (assuming it remains unmaintained/no development), and because the latest version of the program is proprietary, the user loses the freedom they once had when using this program. The GPL essentially forbids this in order to prevent that from happening.