Hi there,
before installing Local on my Mac i would like to know if any existing system installations (like PHP, Nginx, database, …) are changed, updated or overridden, or does Local install those companion applications in its own ecosystem and therefore not target anything already installed on that Mac?
Local doesn’t replace any of those things and instead runs its own “Lightning Services” which are basically different pieces of software typically used on the server (PHP, MySQL, Nginx/Apache, Mailpit, Adminer Evo)
The one thing that might collide with existing software is that Local uses its own “Router” which listens on ports 80/443 and helps resolve a human readable name like mysite.local to the actual port that the WordPress site is listening (like localhost:10006).
If you already have a server listening on those ports, then you have two options:
Stop that other service before starting Local, then stop Local whenever you want to use the other service
Run Local in “localhost” router mode. There are some limitations to running like this, namely no HTTPS. If you want more details on this, check out our help doc: What is Router Mode? - Local