That was a life-changing experience as it led to me dropping out of my Physics degree and eventually going into a computing career.
https://rbanffy.github.io/fun-with-big-computers/fun-with-vm...
BTW, I have updated the container images for VM/370 Sixpack and VM/370 CE today.
Somebody at IBM built an interactive APL interpreter that ran on the 1620, but it seems this was never released:
Experimental personalized array translator system https://dl.acm.org/doi/10.1145/364520.364573
btw, for people who were there at the time, even considering the bare metal assembly nature of IPL, were people already approaching solutions similarly to lispers in the 60s ? aka dynamic generic lists, tree traversals etc