How are Parental Restrictions Implemented? I'm going to be repurposing my laptop as a media center in the near future and I was planning on using a non-admin account for day-to-day usage.  I was thinking of enabling parental controls so I can lockdown what applications are allowed to run but parental controls can be a PITA so I would like to know how it works under-the-hood.  

Is it using seatbelt to implement some form of MAC or does it just make it difficult to launch applications through the UI?
The restrictions are a multitude of features and MDM/MCX controls that apple has for a long time delivered for corporate users and managers to control the OS. Since so many different restrictions can be configured, there is no one implementation. The code that enforces bed times and limits is implemented differently than changing finder to work in a restricted manner.