GPLv3 in a commercial product?

Question

ExtJS/Sencha

There is a small hotel reservation service that I want to write using an ExtJs library on the front. The service itself is not for sale, but simply a form for filling out an application with a subsequent redirect to Sberbank acquiring (payment page). In principle, I can also provide the code, removing the combat passwords to the databases from there and collecting it.
Can I use the free version here?
How strict in general in the Russian Federation with this GPLv3? Will someone really check what library I have connected there and what kind of license it has?

Answer 1

How strict in general in the Russian Federation with this GPLv3? Will someone really check what library I have connected there and what kind of license it has?

Will not check.
But if you run into it and someone out of principle decides to sue you, you will get it in full.
As a library (without modifications) you can use.
If you remake, you will need to publish the changes

Answer 2

> [GNU] GPLv3 in a commercial product?
Well, yes, and why not, this is a free license, that is, by definition , it can be used for commercial programs.
But still, I urge you not to follow bad examples, but to use "version three or later, published by the Free Software Foundation", as recommended .
> Sam[a service] is not for sale
?
> Can I use the free version here?
"Free version" - which one is under the GNU GPL?
As long as you haven't given any reason why you couldn't.
Such might be the need to bundle this library with another program under a license incompatible with the GNU GPL (and in particular with non-free software).
> How strict in general in the Russian Federation with this GPLv3?
Copyright is the same everywhere (well, almost ;-). And so does copyright.
> Whether someone will really check what I there library where connected.
Well, I'm going to try and inquire.