Lamdu features immediate feedback, localized type errors, and live execution on top of projectional editing to create a unique programming experiece. See video:
Version 0.7.1 (Release notes):
The current release is a technology preview. The intention is for it to become a competetive, fully-featured programming language and environment but it will still take us a while.
It can, and has been used to create real applications such as web servers and web sites, but we don't yet recommend using it for a production environment.
If you share our dream and want to help us realize it, join us! A good place to contact us is our gitter chat room.
(btw: you may have also noticed that contribution could help in designing this very web page)