The check of username and email address are made with Ajax dynamically before submitting the form. Password management include: password lifetime, password generator, the registration process requiry to agree site Terms, registered user can delete their account directly from frontend, and registration may require admin approval. All forms are protected by an accessible Ajax Captcha plugin. No hack to the core are needed. AUser Manager use the same mysql table as the core user manager, so you don't need to import/export any user and can switch back to core user component always without loosing data.