Comment by tzs

> The GPL requires the company to send the user a written offer of source code

It should be noted that this is just one of three options that someone who wants to distribute binaries of GPL code can choose from. It's the most commonly chosen one, and one is only available for noncommercial distribution, so the odds are good that this is the option they are using.

The other available option is to accompany the binary with the source code.

That one leads to an interesting possibility where someone could end up with a binary and there is no one obligated to provide source to them. As far as I know this has not actually arisen, but it seems like something that is bound to happen sometime.

Suppose company X decides to make a generic hardware platform that other companies can buy to build their products on. X's platform is basically a small single board computer with WiFi, Bluetooth, dual, USB ports, a couple Ethernet ports, and some GPIO ports. X ports Linux to their hardware.

When X ships a system it comes with an SD card with a Linux distribution installed including their custom kernel. It is configured to boot from the first SD card slot, and then to run a custom login system that looks at the second SD card slot and if there is a card in there it mounts it, looks for an executable on its root name application.exe, and runs that as root. X includes in the box a small thumb drive with a copy of the source code for everything on the SD card.

The idea is that a company Y that wants to make something like a WiFi access point or an air quality monitor can buy these boards from X, put them in a case with whatever peripherals or sensors they need like air quality sensors, write the software for the application, put it on an SD card, and put that in the second SD card slot.

So lets say Y buys 1000 of these systems from X, builds 1000 of their access points or whatever from them, and sells them.

One of their customers asks Y for the source code of the GPL parts. Does Y have to provide it?

I'd say they do not. They are not making copies or derivative works. They are just receiving physical copies from X and passing those on unmodified to their customers. This should fall squarely under the First Sale Doctrine in US copyright law, and similar rules in other jurisdictions.

How about if they ask X for a copy?

X has made copies and derivative works and distributed them. But X satisfied their GPL requirements by including a thumb drive with the source with each board they shipped to Y.