Autism Spectrum Disorder (ASD) is a neurodevelopmental condition characterized by social interaction and communication difficulties, along with narrow and repetitive interests. Being a spectrum disorder, ASD affects individuals with a large range of combinations of challenges along dimensions such as intelligence, social skills, or sensory processing. Hence, any computer-based technology for ASD ought to be customizable to fit the particular profile of each individual that uses it. The main goal of our survey is to collect and characterize the customization support that has been researched for these technologies, which we analyze along clinical and technological dimensions. Our survey revealed that despite its importance, customization support for these technologies remains a subject largely unexplored. Furthermore, we propose alternatives on how to address the limitations identified.