a collection of hard to find zip of SuperSU (no longer maintained),
including my own modification of forcing to NOT use the 'systemless' feature, regardless of whatever Android version you install it on (by default SuperSU will automatically use the 'systemless' feature on Android OS version 6.0 or newer).
Original ZIP-files are signed by Chainfire who is the original developer. The 'nosystemless'-modified ZIP-files are signed by me.
If you are using a custom-ROM, such as lineageOS, you don't need SuperSU (it will break things), just enable super-user in the developers-settings (for both ADB and apps).
The ZIP-files include few binary files (su), an installation code of a daemon/service which runs every boot, the SuperSU managing apk which is installed as a system-app, and an shell-script (in a dummy Edify format - updater-script, updater-script) to use initialize the entire installation process.
SuperSU-v2.46.zip
this is old one, but well-supported.
it hasn't even introduced the 'systemless' feature yet...
SuperSU-v2.78-nosystemless.zip
SuperSU-v2.79-201612051815.zip
SuperSU-v2.79-201612051815-nosystemless.zip
SuperSU-v2.79-SR3-20170114223742.zip
SuperSU-v2.79-SR3-20170114223742-nosystemless.zip