Hi,

I'm evaluating the keycloak to use in a multi-module system in production and I need some help in the following topics:

- Is it possible to define groups of roles? For example, in a scenario using groups as profiles and the roles as resources.

- Single login validation (only allow a single login session per user to avoid account sharing)

- Is there any sample federation provider for RDBMS?

- Are you planning to develop an adapter to PHP web applications? Any community adapter available?

Great Job!

Thank you!