My sense is that this is one of those tools whose descriptions sounds like something unusable until you actually use it and then it likely becomes indespensible

My sense is that this is one of those tools whose descriptions sounds like something unusable until you actually use it and then it likely becomes indespensible for experimentation and particular tasks. Its got elements of a giant remix of concepts from spreadsheets, olde unix, plan9, squeak, various window managers, terminals, standard input/output pipelining. Definitely worth a deeper look.