The Open Radio Access Network (O-RAN) Alliance's most recent innovations are propelling the evolution of RAN deployments, moving away from conventionally closed and specialized hardware implementations and toward virtualized instances running over shared platforms and distinguished by open interfaces. Such progressive decoupling of radio software components from the hardware is paving the road for future efficient and cost-effective RAN deployments. However, there are still a lot of open challenges before O-RAN networks can be successfully deployed.