

It’s not just server-side: A lot of fingerprinting happens client-side, for example using a canvas to check what features your graphics card supports. You can see this in action via services like https://coveryourtracks.eff.org/ or https://amiunique.org/



There are a billion of these frameworks. This site allows you to compare a lot of them, though it does not yet include dev.css:
https://dohliam.github.io/dropin-minimal-css/