From: Mark Tarver on
Here is a project Slime/Emacs people might find interesting. A self
annotating program editor that corrects your mistakes and actually
types ahead of the programmer. The technology uses *real-time type
checking* and is based on Qi technology. The original suggestion is
on qilang.

http://groups.google.co.uk/group/qilang/browse_frm/thread/969a64ddfc831b75?hl=en