NightShift automatically downloads and updates WebKit.
EditByBSEditor: NightShift automatically downloads and updates WebKit, the Safari HTML rendering engine, to the latest nightly version. No user intervention is required, everything is fully automated.

Downloads WebKit nightly build from web server

Mounts the disk image

Creates a backup of the previous version on disk

Copies the new nightly build to its Default location

Option to copy the JavaScript debugger Drosera to disk

Option to launch the new version of WebKit

Option to undo latest install and revert to last version you can free download NightShift 1.6 now.