The global power sector is undergoing an unprecedented transformation driven by the rapid deployment of inverter-based resources (IBRs) alongside the phased retirement of conventional fossil fuel-based synchronous generators. Australia is playing a pivotal role in IBR integration globally and has launched several initiatives to support higher IBR integration. State-of-the-art assessment methods and practices are being developed to better understand and address the complex, emerging challenges facing the power industry. During the renewable energy transition, the technical requirements for connection have been continuously evolving to adapt to the new challenges and technologies of large-scale IBR integration. This paper reviews the evolution of Australian generator connection rules, with a background in high IBR penetration and its impacts on the Australian National Electricity Market (NEM). The insights from the Australian generator connection rules will serve as a valuable reference for other countries in defining their grid codes for integrating renewable energy generators.