Re: subshell differences between /bin/sh and /bin/ksh

[Edgar Fuß]

I fail to answer the first question (while I'd guess kre can), but the answer 
to the second is most probably that ksh (the original one, not pdksh) is 
brilliant in avoiding forks.
If you have shell scripts that use lots of command substitutions (e.g.
foo=$(printf ...), pdksh can be several orders of magnitude faster than any 
other shell I know of.