> Freetz is a toolbox for developers and experienced users to build a modified firmware based on the original firmware for the DSL/LAN/WLAN/VoIP-Routers AVM Fritz!Box and T-Com Speedport (identical hardware) and to transfer this firmware to the device. There are many extension packages available, along with options to remove unwanted functionality from the original firmware.
I am not entirely sure that is what LGPL is about. Unless the router was specifically sold as Open Source. I thought the whole reason for LGPL is that you could use it with other proprietary code?
The article suggests that AVM provided some code but not the build tooling or scripts needed to produce a useful firmware image out of them, or documentation around various opaque variables required for the build, and since they're required to do that, here we are.