The 32bit Windows version is from CHIP.de. It was installed in virtual machine to verify it is actually Netfabb Basic. We have the installer but it's license prohibit us from sharing it, and it also installs Examples with unknown license. This is just an archive to unpack and run. It contains the app, that we are allowed to redistribute.
The 64bit Linux version is from the classroom computers at Faculty of Information Technology, Czech Technical University in Prague. Downloaded from Netfabb website when available, unpacked and later repacked.
The macOS binary is from @aerickson installed on his computer using the 7.4 installer from Netfabb website (no longer available), later zipped. He vouches for it (see #2). Meshes and manuals removed by @hroncok.