I apologize if I should be understanding this more readily but I'm a little new to this and dont understand the LGPL license. Here is the FAQ for it: http://www.qt.io/qt-licensing-terms/

I am making a website that scrapes data from other websites and organizes it in a nice manner. I plan to try and make money off this website through advertising and also by getting commissions from linking to certain sites. I plan on using server-side code that scrapes the website using PyQt4 (which uses Qt). The code scrapes the website and stores the data in a sql database. I then use the sql database to display the webpage.

I think it's fine to use the open source version of Qt right? I'm not selling or really giving any application away. The Qt is being used on server-side code to generate the sql database.

And if it is fine to use the open source, do I have to display a link on the website to the source code of the Qt I'm using? Just trying to fully understand.

closed as off-topic by user22815, Scant Roger, user40980 Dec 1 '15 at 16:04

  • This question does not appear to be about software engineering within the scope defined in the help center.
If this question can be reworded to fit the rules in the help center, please edit the question.

  • Perhaps off-topic here and probably more appropriate on OpenSource. Actually, it is a legal question, so your lawyer can answer. IANAL, but your question probably could have a yes answer. BTW, why don't you make your Qt application open-source? (this does not mean that your database dump should be freely available) – Basile Starynkevitch Nov 30 '15 at 9:28
  • BTW, I am very surprised that you need Qt in a server side application. This is unusal... (Wt & libcurl would perhaps be more relevant ....) – Basile Starynkevitch Nov 30 '15 at 9:31
  • this could be a near duplicate – Basile Starynkevitch Nov 30 '15 at 9:36
  • I'm looking for a server side code that can scrape webpages that render content with javascript. Apparently this can be kind of difficult. I've seen some guides on how to do it with PyQt4 so that's what I'm trying. Oh and im doing the scraping in python so thats why PyQt4 looked even better. – bluemoon12 Nov 30 '15 at 13:14
  • 2
    I'm voting to close this question as off-topic because it is asking for legal interpretation of a third-party license. It should be directed to the Qt developers instead. – user22815 Nov 30 '15 at 20:56

To use the OpenSource version of Qt under the LGPL license, you must meet the following conditions:

  • If you distribute the Qt libraries that you use, then any changes to them must be made public under the LGPL license
  • Users of your application other than you must have the possibility to replace the Qt libraries it uses, either because the libraries are dynamically linked or because they have access to the code under the GPL license. If the Qt libraries are dynamically linked, you have no obligation to release your sources or to use an open-source license.

If you use the application exclusively on your own machines (including any servers that you control), then you are not distributing the software. This means that the conditions of the LGPL license are trivially met, because the set of people that they apply to is empty.
As a side note, there is only one license that includes giving remote access to your software in its definition of "distribution": The AGPL license.

  • Ah ok so thats what I was kind of thinking. Since I'm using it on my server I'm not distributing it to anybody. So I really dont have to do anything then? No links or attribution? From what I'm reading I think thats true... – bluemoon12 Nov 30 '15 at 13:11
  • @bluemoon12: You are right, you don't need to place a link or even attribution on your site. – Bart van Ingen Schenau Nov 30 '15 at 15:55

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