Keychain Access.app hasn't changed in years. But if you're just interested in filling out passwords, then you can use the Passwords settings pane in system settings and/or the password settings screen in Safari.

How so?

There is no application and doing anything from looking for a login detail to editing a password is on a par, interface wise, as editing a registry key on windows.

System Settings has the Password section and there's Keychain Access.