Steam crackers normally use ethane, LPG and naphtha as feedstock for conversion to olefins. Occasionally, heavier hydrocarbons such as gas oils and unconverted oil from hydrocracking units have been utilized. There are some complexes that process very light crudes and condensates directly in a steam cracker. Lummus Technology, CLG (Chevron Lummus Global) and Saudi Aramco have conducted intense joint research over the last several years to understand the implications of steam cracking crudes heavier than very light crudes and condensates with the bulk of the experiments conducted on Arab Light (AL) crude.  The research involved understanding the distribution of molecular species within the whole crude including the very complex structures of asphaltenes. Novel techniques of separation avoiding conventional crude atmospheric and vacuum distillation systems, appropriate catalyst and integrated reactor platforms along with novel heat integration, permits the consistent yield of chemicals to increase to between 70 and 80% for light to medium crudes and higher for very light crudes and condensates. Selective hydrogen addition optimizes the molecular species for optimum cracker yields and maximum cracking heater run lengths. One important objective of the research that led to successful commercialization in 2020, was the elimination of low-value stream production such as pyrolysis gas oils and other orphan streams. Heat integration, operability and reliability were key parameters in the development as was the very significant reduction of overall CAPEX, OPEX, plot space and CO₂ footprint. Some of the salient features of this technology will be discussed in this paper.