Many people use PF_RING just as a “better” libpcap. PF_RING is much more than that, as it can significantly simplify the design of network monitoring applications as well better exploit modern multi-core architectures and network adapters.
For those willing to dive into PF_RING, I have released an updated user’s guide that can introduce you to the PF_RING API. Do not forget that there’s a detailed PF_RING tutorial available, as well several code examples for showing in practice what PF_RING can offer you.