Requirements

Server and WordPress

Roleline doesn't add database tables. It stores its backups and settings as WordPress options and changes roles the way WordPress does, in the wp_user_roles option.

Who can use it

Users → Roles is for people with the roleline_manage_roles capability. Administrators get it when Roleline is activated. You can give it to another role (a "Role manager", say): people who aren't administrators can then manage roles, but only grant capabilities they have themselves.

To give users roles, people also need WordPress's promote_users capability, as usual.

Works alongside

• WooCommerce and other plugins that add roles and capabilities: their capabilities are listed in their own groups. WooCommerce's are recognised by name even while WooCommerce is inactive.
• Multisite: roles are per site, so Roleline works on each site's Users → Roles. See Multisite.
• Other role editors (User Role Editor, Members): they edit the same WordPress roles, so they can be used side by side, but there's no need to. Roleline's backups only cover changes made through Roleline, so make changes in one place.

Roles defined in code

Some sites define their roles in code with the $wp_user_roles global. WordPress then never saves role changes, so Roleline shows the roles but says changes can't be saved.