How to find out what modules are adding links to a menu? I was wondering if there's any way to find out what modules are adding links to what menus using hook_menu()? I don't care if it's a module or custom code added to Drupal core, I just need to know. There's a link showing up in my main menu and I have no idea what's putting it there. I'd really rather not go through every single module and check their menu hooks.
You're after module_implements(). It will allow you to specify the hook (in this case 'menu') and then get an array of module names back.
Of course, you'll still need to manually open the files to check, but you should be able to narrow it down from the menu path and title.

It might be worth flushing the caches too.