don't confuse the URL structure with the application design. just because the url is /user/87/edit doesn't mean that there is a file called edit inside a folder called 87. almost any modern web development framework lets you create whatever URLs you want. i'm sure, internally, that every user's edit panel is powered by the same code.
It's a Rails application and it does reflect the structure. It's the edit action on a controller, likely the UsersController. It looks like they tried to implement a user management system using has_secure_password and didn't know enough to do it properly.
They therefore created a default resource structure (probably using the rails scaffold generator command) which includes the id in the URL on all member routes, including the route for the edit action.
