[chasil]

The POSIX shell actually devolved from Korn and bash.

ksh88 worked very hard to compile its data segment in under 64k so it would work on Xenix running on a 286 and similarly constrained systems. The code was sphagetti gymnastics in achieving this.

The POSIX shell standard removed many features of the ksh88 language. It appears that this was done in an attempt to maintain a small footprint, but clarify the code.

This is good for embedded systems, but bad if you need arrays.