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Comment by enriquto | Hacker News Reader

> Installation of Qt binaries will require a Qt Account

How is this compatible wit the LGPL? Can't I host a compiled copy of Qt and let the world install it?

> Can't I host a compiled copy of Qt and let the world install it?

Of course you can do that, as long as you respect the LGPL. That's what pretty much every Linux distribution is doing. It's just that the old Qt offline installer by the QtCompany is no longer available.

Qt is released under two different licenses: there's the open source release and the commercial release.

Qt hasn't for a while distributed binaries for the open source release, but there were publicly downloadable binaries for the trial version of the commercial release which is what has now gone. But as you say, nothing stops _others_ from distributing binaries for the open source release.

The Qt company owns the copyright to the Qt source code so they can sell (L)GPL exceptions. Bundling LGPL code in a binary, as mobile may require, instead of loading as dynamic library, requires you to get an LGPL exception from the copyright holder (or provide an object file for the user to relink). Other licenses, like Apache and the EPL, do not have this issue.

Companies can do this for open source projects. They require you to sign a contributor agreement handing over over copyright or require you license the code to them under the MIT. For the most part, differs based on region and IANAL.

Edit: corrected in () that you can comply with the LGPL with static binaries with providing an object file to the user to relink with.

> Bundling LGPL code in a binary, as mobile may require, instead of loading as dynamic library, requires you to get an LGPL exception from the copyright holder.

How come? The LGPL allows people to distribute statically compiled binaries that use Qt, you do not need an exception for that.

> The LGPL allows people to distribute statically compiled binaries that use Qt

Hmmm... you can as long as you provide an object. Learned something new today. I do remember Mike discussing that on Coder Radio that would be an issue in the security industry. I assuming there were some aerospace libraries that are NDAed/restricted by national security laws.

https://stackoverflow.com/questions/10130143/gpl-lgpl-and-st...

http://www.gnu.org/licenses/gpl-faq.html#LGPLStaticVsDynamic

Is this possible on iOS? Not familiar with iOS dev, but I assume Apple may have some TOS problems with that.

It is, Cisco does it for one of their apps which uses Gstreamer on iOS.

See the note here at the end: https://github.com/freedesktop/gstreamer/blob/master/README....

Can’t you bundle it in a binary as long as you provide an upgrade path for the QT part? I know this doesn’t work for mobile because users can’t do it due to the app stores, but for an embedded MCU application you could allow re-linking and reflashing of the hardware.

If you compiled it yourself, yes. The Qt source code is available under the LGPL (among other options), the binaries provided on the Qt website are not.

Correct, you can do exactly that.

So how does this make Qt "anti open-source"? I'm not saying that they aren't, but they are under no obligation to provide binaries to anybody (under any free software license). Many bona-fide free software packages do not provide binaries at all.

You won't get any sources to 5.15.x after 5.16 or 6 is out.

So these mirrors don't exist then? https://download.qt.io/static/mirrorlist/

Again: to 5.15.x after 5.16 or 6 is out.

Or, in more words as Qt pusts it:

> Starting with Qt 5.15, long term support (LTS) will only be available to commercial customers. This means open-source users will receive patch-level releases of 5.15 until the next minor release will become available. This means that we will handle Qt 5.15 in the same way as e.g. 5.13 or 5.14 for open source users.

It has nothing to do whether mirrors do exist or not, when there will be nothing to mirror.

That's incorrect. The 5.15 branch is and will be public. Most if not all changes to that branch will go via the dev (Qt 6) branch, which is also public.

Straight from the Qt (link above):

Qt have indicated to KDE that they'll be lagging the open source code behind the binaries by upwards of twelve months. [0]

> But last week, the company suddenly informed both the KDE e.V. board and the KDE Free QT Foundation that the economic outlook caused by the Corona virus puts more pressure on them to increase short-term revenue. As a result, they are thinking about restricting ALL Qt releases to paid license holders for the first 12 months. They are aware that this would mean the end of contributions via Open Governance in practice.

[0] https://mail.kde.org/pipermail/kde-community/2020q2/006098.h...

Sure you can, but QT will not be responsible for compatibility of your binaries, and I for example would not use yours, instead I'll try use some official biniries from Canonical for example even older ones.

Obviously you can. The officially sanctioned Qt binaries will require a Qt account before they can be downloaded though.

As a matter of fact, all the Linux distribution distribute Qt and I don't remember creating an Qt Account for downloading the KDE/Qt applications I use and Plasma from my distro.

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