User management script/class recommendations?

[jopperdepopper]

Hi,

 

currently sketching out a new project that needs a solid user management solution, having multiple levels of permissions would be a requirement. (apart from the basics like registration/login/forgot password etc.)

 

Can anybody recommend a good and flexible out-of-the-box solution for this? Ofc free would be nice

Would also be nice if it is written in a transparent way, so in case I need to make modifications it doesn't require a 3-month study...  :-\

 

Thanks,

 

Job