The Sifflet visual functional programming language and aid to understanding recursive functions (http://mypage.iu.edu/~gdweber/software/sifflet/home.html)

#18Sifflet crashes when applying a function if some connections are missing.

18 Sifflet crashes when applying a function if some connections are missing.

"PS. I presume you know that you can crash the whole of Sifflet by something as trivial as hitting the "apply" button when some connections are missing, and that closing all of the program windows leaves the executable still running but with no way to kill it. (I'm not sure why Ctrl+C is no-op...)" -- email from Andrew Coppin, 2010 Nov 01.

O: 2010 nov 3 R: Andrew Coppin P: HIGH C: 2012 Jun 27 -- unable to duplicate either part of this at this time; must have been fixed earlier. Though it might be that the "no way to kill it" issue persists on MS Windows.