re: Software Licensing: What is the Copyleft VIEW POST


Good overview. I would argue that the more strict versions of copy-left licenses are a bit more controversial. E.g. AGPL v3 is used a lot by companies that want to restrict people's freedom of what they can do with the software without paying for a commercial license. I've always found this ironical.

A reason contract licenses such as Apache 2.0 or simple copyright waivers like the MIT and BSD licenses are extremely popular on Github is that they are a lot less restrictive on users. There are a few funnily worded variants of the MIT license that basically state "do whatever the F*** you want. It's a model that works well for authors of small libraries that mainly just want to remove obstacles for people to actually enjoy their work. I usually slap the MIT license on anything I put up on Github.

Some of the more popular GPL projects like Linux use GPLv2. Part of the reason for the success of Linux is a few unintended loopholes in the wording of this license allowed electronics manufacturers and linux distribution providers to bundle non OSS software and get away with that. This lead to GPLv3 but the linux ecosystem never moved to that. IMHO without these loopholes, we'd probably be using some BSD variant by now. E.g. Android would not be very practical in its current form with a stricter license requiring everything to be open sourced.

Most big companies seem to gravitate to Apache style licenses as it just uncomplicates the legal due diligence of actually using each other's software. I worked in Nokia around the time it was doing Linux phones and I can tell you that legal departments were very defensive when it came to their competitors finding any excuse to go to court. They dealt with copyright, trademark, and patent issues all the time and were settling cases (mostly in favor of Nokia because they were good) for very non trivial amounts of dollars all the time.

This is true for most big corporations. Most of them would not touch anything AGPL licensed because it's just not worth the risk and actively enforce policies to prevent this happening. GPLv2 was OK (obviously) but they vastly preferred Apache 2.0 and MIT style licenses.


The reason Linux is still GPLv2 is because they didn't include "or later version" is the license text, which basically prevents them from upgrading to GPLv3. If they wanted to change this they need to track down every contributor to ask for permission.


Technically, yes. But the net effect has been that it's become very popular with companies that depend on the unfixed loopholes. You are right that the reason switching for Linux never happened is also that it would require permission from the copyright holders.

But if I recall correctly, Linus Torvalds was biased against this in any case (probably for the reasons I outlined). Either way, the license has served Linux well.

I would even say that without the GPL attached to it (with linking exception) the Linux kernel wouldn't have been where is was now.

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