[abrax3141]

Two good questions; Two different answers.

First, re "ironically":

Short answer: Lisp and IPL were competitors for the list&symbol-processing community of early AI. IPL invented a lot of what Lisp implemented in nicer syntax -- in effect, Lisp was an HLL for IPL. Lisp (obviously) won and now we're (ironically) emulating IPL in Lisp in order to emulate Lisp's underlying machine in the HLL that sits on top of that machine. (Actually - ironically^2 - SLIP won ... see below.)

Longer answer: This whole corner of language development was full of ironies. SLIP (Weizenbaum's approach to list processing) was a plug-in for Fortran (originally) and shortly thereafter, MAD. Just as Lisp wiped out IPL, it also wiped out SLIP. Ironically, today we do what Weizenbaum envisioned: Write in powerful general HLLs and add in specialized packages for things like list processing. So, in the end, SLIP won!

[Rochus]

Thanks. I read about IPL for the first time in McCarthy's history of Lisp paper, but never took a closer look. I now also see the irony.