Qt elevator pitch to IT

[yalnte]

Hi, how have people sold the idea of using Qt to their IT departments? I tried informally discussing with IT today but the guy I spoke to was put off by the ‘Try-Buy’ spiel on the Qt website and had little understanding of the concepts of GPL/LGPL.

I just want to develop some UIs that dynamically link to the LGPL compliant bits of Qt. I have no need / time to modify Qt. To get Qt installed on my system I need a link to a self contained full installer and a clear rationale as to what LGPL means and what the licensing terms are. This used to be a lot easier in the olden days!

Any informed advice appreciated!

Edit: Just to add this is a Windows based system. We’ve been using Qt on Linux for some time but the providers are different.

[SGaist]

Hi,

Well... in the good old days there were only two licences and not for all the platforms so it was not really that easier :-D.

As for your use case, LGPL looks like the licence you want. No need to share your code, your users shall be able to switch Qt for a different version hence the dynamic build is the recommended way.

For installation, use the online installer as it provides access to current and older versions of Qt.

As for the pitch, this is a voluntary driven user forum, you likely won't find the marketing department you are looking for :-)

[yalnte]

@SGaist Thanks - I’m not in a position to negotiate with IT unfortunately. I need a standalone installer and an easy to access sales pitch with clear arguments as to when Qt LGPL is valid.

I suspect other potential users have faced this problem. Qt marketing seems to be pitched at growth markets with lots of cash and urgent requirements. I have zero budget and no prospect of ever establishing Qt as a tool in our department without using LGPL as an entry point.

[SGaist]

Offline installers stopped after Qt 5.15 for non commercial customer.

[VRonin]

@yalnte said in Qt elevator pitch to IT:

To get Qt installed on my system I need a link to a self contained full installer

You can find the self contained archive by navigating https://download.qt.io/online/qtsdkrepository/ or you can use the aqtinstall python script

and a clear rationale as to what LGPL means and what the licensing terms are.

Is this used internally in your organisation or do you need to distribute it? If the first is true then your software complies with GPL3 (see the FAQ) and you don't have anything to worry about

[yalnte]

@VRonin Thanks - internal only so agree about GPLin principle but trying to closedown any doubt about need to make our source code available in some hypothetical future situation.

IT need an audit trail of easy to understand points so I’m hoping someone has already invented this wheel! 😀

[VRonin]

The audit trail is actually really short. private use / internal use is always allowed:
from https://www.gnu.org/licenses/gpl-faq.en.html

Does the GPL require that source code of modified versions be posted to the public?
The GPL does not require you to release your modified version, or any part of it. You are free to make modifications and use them privately, without ever releasing them. This applies to organizations (including companies), too; an organization can make a modified version and use it internally without ever releasing it outside the organization.
Is making and using multiple copies within one organization or company “distribution”?
No, in that case the organization is just making the copies for itself. As a consequence, a company or other organization can develop a modified version and install that version through its own facilities, without giving the staff permission to release that modified version to outsiders.

need to make our source code available in some hypothetical future situation.

If you distribute your software outside your organisation in binary form then you'd need to provide a "written offer to provide source code" but if this is the case then LGPL would plug that gap, I'd cross this bridge only if you absolutely need to

[JKSH]

@yalnte said in Qt elevator pitch to IT:

To get Qt installed on my system I need a link to a self contained full installer and a clear rationale as to what LGPL means and what the licensing terms are. This used to be a lot easier in the olden days!

If you don't need the latest and greatest, the direct link to the Qt 5.12.11 LTS offline installer (released just last month) is at https://download.qt.io/official_releases/qt/5.12/5.12.11/qt-opensource-windows-x86-5.12.11.exe

Clear rationale to what LGPL means in your case:

• Your app must clearly acknowledge the use of the LGPL library and provide the full text of the license.
• Your app must use the LGPL'ed library in DLL form, as opposed to statically linking it into your app. (Technically there is more to this story, but if you just stick to DLLs everything will be fine and simple)
• You must offer to provide the full source code of the LGPL'ed library. (A copy of the code is in the installer)
• You don't need to provide the source code of your app.
• The nice thing to do is to contribute back to the community of the LGPL'ed library in some way (e.g. helping out in this forum, submitting bug reports, submitting patches to the library, telling people about the library, etc.) This is not a legal requirement, but it is the nice thing to do since you're getting the library for free.

That's it, really.

elevator pitch

"Qt is an intuitive, cross-platform toolkit that blows its competitors out of the water. Qt-based apps are easy to write and easy to maintain*. It provides all kinds of functionality, from GUIs to 3D image rendering to networking to database access, and more -- all in one coherent package."

(*assuming that the programmer follows best practices)