AVIF is the example. It supports palette-based blocks in addition to classic DCT with sophisticated deringing. There's also https://pngquant.org https://pngquan

AVIF is the example. It supports palette-based blocks in addition to classic DCT with sophisticated deringing. There's also https://pngquant.org https://pngquant.org (palette may seem banal, but it is a type of vector quantization) and https://github.com/richgel999/rdopng https://github.com/richgel999/rdopng