@abga,
I only learned of it from
sbotools, but as it stubbornly tried to download the 4.4.14 kernel source I decided to look around...
... and what do you know - it's shipped with every kernel source - mine is form 4.18.6
all one has to do is
make && make install to access it.
Thankfully Slackware is the best make && make install distro of them all...