Does linux support the functionality provided by Windows HKEY_CLASSES_ROOT URL protocol trigger?

This windows registry magic: [HKEY_CLASSES_ROOT\shotgun] @="URL:example Protocol" # <---- URL for this example is example.com "URL Protocol"="" [HKEY_CLASSES_ROOT\example\shell] [HKEY_CLASSES_ROOT\example\shell\open] [HKEY_CLASSES_ROOT\example\shell\open\command] @="\"python\" \"myContextMenuTriggerScript.py\" \"%1\"" Source for this above So I can't say I understand it but apparently, via any protocol at all, and especially http or https I guess, when you visit a certain web page in your browser, in Windows with these keys and values stored in your registry, a python script will run on that webpage and do whatever you want in the context of that webpage. I use this functionality every day. I am looking for this functionality, safely, in Linux and my only question is, does Linux have something LIKE the registry (as awful as that is to say) that will allow me to cause say Ubuntu to react to my visiting a webpage... and run a script... and what might that piece of the system be called? Would you use gconftool to register a protocol this way? Is this safe to do? <------- Is it really the equivalent of doing it with Windows?