In pngcrush, I'm seeing as much improvement again in beta3 as beta2 delivered. Typical "user" times for three test directories of multiple images having 500k IDAT chunks and 720 columns, using "pngcrush -n" (read-only): 1.1.4 1.1.4+beta2 1.1.4+beta3 9.22 8.42 7.56 29.88 27.17 23.21 21.31 18.58 16.69 9.90 8.62 7.49 Glenn