There are TONS of advantages to ksh93 over bash. -Floating point math, not just integer -Coprocess syntax that is correct and compliant -Genuine Korn retains

There are TONS of advantages to ksh93 over bash. -Floating point math, not just integer -Coprocess syntax that is correct and compliant -Genuine Korn retains variables in control structures -Lots more, detailed in the Korn & Bolsky ksh93 book The language specification for ksh93 is large and powerful, and bash doesn't approach it.