I finally could get GNU APL work as a REPL inside Vim! See: http://www.vim.org/scripts/script.php?script_id=4887
(for unix/linux only; uses FIFO and external shell commands: "tail", "gnu apl", one subshell) tiny bug: the subshell is still alive after leaving Vim; I have to asked some shell-guru. Regards, -- Thomas Baruchel
