Things have changed just a tad with Solaris 8, though. We now have a process known as Role-based Access Control (RBAC). Although sudo is a bit easier to set up, with RBAC you no longer need to compile another program to provide this functionality.
UNIX has always allowed users to be granted access privileges for running programs that they normally don't have access to. Even with modern-day Solaris, you still have the ability to set your user id and group id, as well as access control lists, and you can still use the venerable third-party sudo program.