There are Multics QEDX sources, but I haven't run across QED - however, there is an overview of it's use and commands in the General Electric June 1969 Multics Condensed Guide (http://bitsavers.org/pdf/honeywell/multics/swenson/6906.multics-condensed-guide.pdf)

I pulled the QEDX source at put it at https://ban.ai/~jhj/misc/qedx/ for easy access - this is the MR12.5 version and last modified in 1989, sadly, I don't ever recall seeing the BCPL QED. [ I'll be sure to remember now if I see it. ]

[ Somewhat off-topic ] How about Yale 'Z' as long as we're talking editors? Or another editor (that I very much like) is the 'G' editor, which has a long history, originating on Honeywell 6000 GCOS/TSS, originally written in B: https://github.com/ascheepe/g-editor - works nicely today. There is also the Ecce editor, which includes versions in IMP, BASIC, C, BCPL, and FORTRAN at http://history.dcs.ed.ac.uk/archive/apps/ecce/ - bringing Ecce up on Multics is an item on my todo list.

-- Jeff - https://ban.ai/multics/