In case your personal chronological event horizon is, like mine,
less than two years, edif lets you use terminal-based editors like
vim and nano to create and edit apl functions while edif2 lets you
use emacs and similar editors. (The latter, edif2, works well
with aplwrap as well as with standard terminal-based apl. edif,
on the other hand, confuses aplwrap terribly--aplwrap doesn't
understand the full range of terminal controls terminal editors
use.)