Updated: April 3, 2016
This module adds the ability to add fields to users.
There are "Profile Types". Each profile type has its own set of fields. These are regular Drupal fields and so field related modules work with them, such as the Conditional Fields module, and you can Manage the display of the fields like you can on any other fieldable entity type.
The module adds general permissions and permissions specific to each Profile type that you create. The general permissions are "administer profile types" and "administer profiles". Each profile type has the following permissions: edit own, edit any, view own, view any.
Go to structure -> Profile Types to see a listing of profile types. On this page, there is also a link to add a profile type or import a profile type. Each profile type can be exported/imported using ctools and/or features. The "Main profile" profile type is added automatically when the module is installed. When editing a profile type, you can check the "Show during user account registration" checkbox if you want the fields to show up on the user regisration page.